diff --git a/config.c b/config.c
index 1f5b3efa..94b31b70 100644
--- a/config.c
+++ b/config.c
@@ -9,11 +9,17 @@
 #include <unistd.h>
 
 #include "config.h"
+#include "criteria.h"
 
 void init_default_config(struct mako_config *config) {
-	init_default_style(&config->style);
+	wl_list_init(&config->criteria);
+	struct mako_criteria *global_criteria = create_criteria(config);
+	init_default_style(&global_criteria->style);
+
+	init_empty_style(&config->hidden_style);
+	config->hidden_style.format = strdup("(%h more)");
+	config->hidden_style.spec.format = true;
 
-	config->hidden_format = strdup("(%h more)");
 	config->output = strdup("");
 	config->max_visible = 5;
 
@@ -26,8 +32,12 @@ void init_default_config(struct mako_config *config) {
 }
 
 void finish_config(struct mako_config *config) {
-	finish_style(&config->style);
-	free(config->hidden_format);
+	struct mako_criteria *criteria, *tmp;
+	wl_list_for_each_safe(criteria, tmp, &config->criteria, link) {
+		destroy_criteria(criteria);
+	}
+
+	finish_style(&config->hidden_style);
 	free(config->output);
 }
 
@@ -59,11 +69,116 @@ void init_default_style(struct mako_style *style) {
 	memset(&style->spec, true, sizeof(struct mako_style_spec));
 }
 
+void init_empty_style(struct mako_style *style) {
+	memset(style, 0, sizeof(struct mako_style));
+}
+
 void finish_style(struct mako_style *style) {
 	free(style->font);
 	free(style->format);
 }
 
+// Update `target` with the values specified in `style`. If a failure occurs,
+// `target` will remain unchanged.
+bool apply_style(struct mako_style *target, const struct mako_style *style) {
+	// Try to duplicate strings up front in case allocation fails and we have
+	// to bail without changing `target`.
+	char *new_font = NULL;
+	char *new_format = NULL;
+
+	if (style->spec.font) {
+		new_font = strdup(style->font);
+		if (new_font == NULL) {
+			fprintf(stderr, "allocation failed\n");
+			return false;
+		}
+	}
+
+	if (style->spec.format) {
+		new_format = strdup(style->format);
+		if (new_format == NULL) {
+			fprintf(stderr, "allocation failed\n");
+			return false;
+		}
+	}
+
+	// Now on to actually setting things!
+
+	if (style->spec.width) {
+		target->width = style->width;
+		target->spec.width = true;
+	}
+
+	if (style->spec.height) {
+		target->height = style->height;
+		target->spec.height = true;
+	}
+
+	if (style->spec.margin) {
+		target->margin = style->margin;
+		target->spec.margin = true;
+	}
+
+	if (style->spec.padding) {
+		target->padding = style->padding;
+		target->spec.padding = true;
+	}
+
+	if (style->spec.border_size) {
+		target->border_size = style->border_size;
+		target->spec.border_size = true;
+	}
+
+	if (style->spec.font) {
+		free(target->font);
+		target->font = new_font;
+		target->spec.font = true;
+	}
+
+	if (style->spec.markup) {
+		target->markup = style->markup;
+		target->spec.markup = true;
+	}
+
+	if (style->spec.format) {
+		free(target->format);
+		target->format = new_format;
+		target->spec.format = true;
+	}
+
+	if (style->spec.actions) {
+		target->actions = style->actions;
+		target->spec.actions = true;
+	}
+
+	if (style->spec.default_timeout) {
+		target->default_timeout = style->default_timeout;
+		target->spec.default_timeout = true;
+	}
+
+	if (style->spec.ignore_timeout) {
+		target->ignore_timeout = style->ignore_timeout;
+		target->spec.ignore_timeout = true;
+	}
+
+	if (style->spec.colors.background) {
+		target->colors.background = style->colors.background;
+		target->spec.colors.background = true;
+	}
+
+	if (style->spec.colors.text) {
+		target->colors.text = style->colors.text;
+		target->spec.colors.text = true;
+	}
+
+	if (style->spec.colors.border) {
+		target->colors.border = style->colors.border;
+		target->spec.colors.border = true;
+	}
+
+	return true;
+}
+
 static bool parse_int(const char *s, int *out) {
 	errno = 0;
 	char *end;
@@ -150,89 +265,74 @@ static bool parse_color(const char *color, uint32_t *out) {
 	return true;
 }
 
-static bool apply_config_option(struct mako_config *config, const char *section,
-		const char *name, const char *value) {
-	// First try to parse this as a global option.
-	if (section == NULL) {
-		if (strcmp(name, "max-visible") == 0) {
-			return parse_int(value, &config->max_visible);
-		} else if (strcmp(name, "output") == 0) {
-			free(config->output);
-			config->output = strdup(value);
-			return true;
-		} else if (strcmp(name, "sort") == 0) {
-			if (strcmp(value, "+priority") == 0) {
-				config->sort_criteria |= MAKO_SORT_CRITERIA_URGENCY;
-				config->sort_asc |= MAKO_SORT_CRITERIA_URGENCY;
-			} else if (strcmp(value, "-priority") == 0) {
-				config->sort_criteria |= MAKO_SORT_CRITERIA_URGENCY;
-				config->sort_asc &= ~MAKO_SORT_CRITERIA_URGENCY;
-			} else if (strcmp(value, "+time") == 0) {
-				config->sort_criteria |= MAKO_SORT_CRITERIA_TIME;
-				config->sort_asc |= MAKO_SORT_CRITERIA_TIME;
-			} else if (strcmp(value, "-time") == 0) {
-				config->sort_criteria |= MAKO_SORT_CRITERIA_TIME;
-				config->sort_asc &= ~MAKO_SORT_CRITERIA_TIME;
-			}
-			return true;
-		} else {
-			// We want to try the style options now, so keep going.
-		}
-	} else {
-		// TODO: criteria support
-		if (strcmp(section, "hidden") != 0) {
-			fprintf(stderr, "Only the 'hidden' section is currently supported\n");
-			return false;
-		}
-
-		if (strcmp(name, "format") == 0) {
-			free(config->hidden_format);
-			config->hidden_format = strdup(value);
-			return true;
-		} else {
-			fprintf(stderr, "Only 'format' is supported in the 'hidden' section\n");
-			return false;
+static bool apply_config_option(struct mako_config *config, const char *name,
+		const char *value) {
+	if (strcmp(name, "max-visible") == 0) {
+		return parse_int(value, &config->max_visible);
+	} else if (strcmp(name, "output") == 0) {
+		free(config->output);
+		config->output = strdup(value);
+		return true;
+	} else if (strcmp(name, "sort") == 0) {
+		if (strcmp(value, "+priority") == 0) {
+			config->sort_criteria |= MAKO_SORT_CRITERIA_URGENCY;
+			config->sort_asc |= MAKO_SORT_CRITERIA_URGENCY;
+		} else if (strcmp(value, "-priority") == 0) {
+			config->sort_criteria |= MAKO_SORT_CRITERIA_URGENCY;
+			config->sort_asc &= ~MAKO_SORT_CRITERIA_URGENCY;
+		} else if (strcmp(value, "+time") == 0) {
+			config->sort_criteria |= MAKO_SORT_CRITERIA_TIME;
+			config->sort_asc |= MAKO_SORT_CRITERIA_TIME;
+		} else if (strcmp(value, "-time") == 0) {
+			config->sort_criteria |= MAKO_SORT_CRITERIA_TIME;
+			config->sort_asc &= ~MAKO_SORT_CRITERIA_TIME;
 		}
+		return true;
 	}
 
-	// Now try to match on style options.
-	struct mako_style *style = &config->style;
+	return false;
+}
+
+static bool apply_style_option(struct mako_style *style, const char *name,
+		const char *value) {
+	struct mako_style_spec *spec = &style->spec;
 
 	if (strcmp(name, "font") == 0) {
 		free(style->font);
-		style->font = strdup(value);
-		return true;
+		return spec->font = !!(style->font = strdup(value));
 	} else if (strcmp(name, "background-color") == 0) {
-		return parse_color(value, &style->colors.background);
+		return spec->colors.background =
+			parse_color(value, &style->colors.background);
 	} else if (strcmp(name, "text-color") == 0) {
-		return parse_color(value, &style->colors.text);
+		return spec->colors.text = parse_color(value, &style->colors.text);
 	} else if (strcmp(name, "width") == 0) {
-		return parse_int(value, &style->width);
+		return spec->width = parse_int(value, &style->width);
 	} else if (strcmp(name, "height") == 0) {
-		return parse_int(value, &style->height);
+		return spec->height = parse_int(value, &style->height);
 	} else if (strcmp(name, "margin") == 0) {
-		return parse_directional(value, &style->margin);
+		return spec->margin = parse_directional(value, &style->margin);
 	} else if (strcmp(name, "padding") == 0) {
-		return parse_int(value, &style->padding);
+		return spec->padding = parse_int(value, &style->padding);
 	} else if (strcmp(name, "border-size") == 0) {
-		return parse_int(value, &style->border_size);
+		return spec->border_size = parse_int(value, &style->border_size);
 	} else if (strcmp(name, "border-color") == 0) {
-		return parse_color(value, &style->colors.border);
+		return spec->colors.border = parse_color(value, &style->colors.border);
 	} else if (strcmp(name, "markup") == 0) {
 		style->markup = strcmp(value, "1") == 0;
-		return style->markup || strcmp(value, "0") == 0;
+		return spec->markup = style->markup || strcmp(value, "0") == 0;
 	} else if (strcmp(name, "format") == 0) {
 		free(style->format);
-		style->format = strdup(value);
-		return true;
+		return spec->format = !!(style->format = strdup(value));
 	} else if (strcmp(name, "default-timeout") == 0) {
-		return parse_int(value, &style->default_timeout);
+		return spec->default_timeout =
+			parse_int(value, &style->default_timeout);
 	} else if (strcmp(name, "ignore-timeout") == 0) {
 		style->ignore_timeout = strcmp(value, "1") == 0;
-		return style->ignore_timeout || strcmp(value, "0") == 0;
-	} else {
-		return false;
+		return spec->ignore_timeout = (
+				style->ignore_timeout || strcmp(value, "0") == 0);
 	}
+
+	return false;
 }
 
 static bool file_exists(const char *path) {
@@ -289,34 +389,72 @@ int load_config_file(struct mako_config *config) {
 	int lineno = 0;
 	char *line = NULL;
 	char *section = NULL;
+
+	struct mako_criteria *criteria = global_criteria(config);
+
 	size_t n = 0;
 	while (getline(&line, &n, f) > 0) {
 		++lineno;
 		if (line[0] == '\0' || line[0] == '\n' || line[0] == '#') {
 			continue;
 		}
+
 		if (line[strlen(line) - 1] == '\n') {
 			line[strlen(line) - 1] = '\0';
 		}
+
 		if (line[0] == '[' && line[strlen(line) - 1] == ']') {
 			free(section);
 			section = strndup(line + 1, strlen(line) - 2);
+			if (strcmp(section, "hidden") == 0) {
+				// Skip making a criteria for the hidden section.
+				criteria = NULL;
+				continue;
+			}
+			criteria = create_criteria(config);
+			if (!parse_criteria(section, criteria)) {
+				fprintf(stderr, "[%s:%d] Invalid criteria definition\n", base,
+						lineno);
+				ret = -1;
+				break;
+			}
 			continue;
 		}
+
 		char *eq = strchr(line, '=');
 		if (!eq) {
 			fprintf(stderr, "[%s:%d] Expected key=value\n", base, lineno);
 			ret = -1;
 			break;
 		}
+
+		bool valid_option = false;
 		eq[0] = '\0';
-		if (!apply_config_option(config, section, line, eq + 1)) {
+
+		struct mako_style *target_style;
+		if (section != NULL && strcmp(section, "hidden") == 0) {
+			// The hidden criteria is a lie, we store the associated style
+			// directly on the config because there's no "real" notification
+			// object to match against it later.
+			target_style = &config->hidden_style;
+		} else {
+			target_style = &criteria->style;
+		}
+
+		valid_option = apply_style_option(target_style, line, eq + 1);
+
+		if (!valid_option && section == NULL) {
+			valid_option = apply_config_option(config, line, eq + 1);
+		}
+
+		if (!valid_option) {
 			fprintf(stderr, "[%s:%d] Failed to parse option '%s'\n",
 				base, lineno, line);
 			ret = -1;
 			break;
 		}
 	}
+
 	free(section);
 	free(line);
 	fclose(f);
@@ -362,7 +500,8 @@ int parse_config_arguments(struct mako_config *config, int argc, char **argv) {
 		}
 
 		const char *name = long_options[option_index].name;
-		if (!apply_config_option(config, NULL, name, optarg)) {
+		if (!apply_style_option(&global_criteria(config)->style, name, optarg)
+				|| apply_config_option(config, name, optarg)) {
 			fprintf(stderr, "Failed to parse option '%s'\n", name);
 			return -1;
 		}
diff --git a/criteria.c b/criteria.c
new file mode 100644
index 00000000..4d1ebb61
--- /dev/null
+++ b/criteria.c
@@ -0,0 +1,300 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <strings.h>
+#include <wayland-client.h>
+#include "mako.h"
+#include "config.h"
+#include "criteria.h"
+#include "notification.h"
+
+struct mako_criteria *create_criteria(struct mako_config *config) {
+	struct mako_criteria *criteria = calloc(1, sizeof(struct mako_criteria));
+	if (criteria == NULL) {
+		fprintf(stderr, "allocation failed\n");
+		return NULL;
+	}
+
+	wl_list_insert(config->criteria.prev, &criteria->link);
+	return criteria;
+}
+
+void destroy_criteria(struct mako_criteria *criteria) {
+	wl_list_remove(&criteria->link);
+
+	finish_style(&criteria->style);
+	free(criteria->app_name);
+	free(criteria->app_icon);
+	free(criteria->category);
+	free(criteria->desktop_entry);
+	free(criteria);
+}
+
+bool match_criteria(struct mako_criteria *criteria,
+		struct mako_notification *notif) {
+	struct mako_criteria_spec spec = criteria->spec;
+
+	if (spec.app_name &&
+			strcmp(criteria->app_name, notif->app_name) != 0) {
+		return false;
+	}
+
+	if (spec.app_icon &&
+			strcmp(criteria->app_icon, notif->app_icon) != 0) {
+		return false;
+	}
+
+	if (spec.actionable &&
+			criteria->actionable == wl_list_empty(&notif->actions)) {
+		return false;
+	}
+
+	if (spec.urgency &&
+			criteria->urgency != notif->urgency) {
+		return false;
+	}
+
+	if (spec.category &&
+			strcmp(criteria->category, notif->category) != 0) {
+		return false;
+	}
+
+	if (spec.desktop_entry &&
+			strcmp(criteria->desktop_entry, notif->desktop_entry) != 0) {
+		return false;
+	}
+
+	return true;
+}
+
+bool parse_boolean(const char *string, bool *out) {
+	if (strcasecmp(string, "true") == 0 || strcmp(string, "1") == 0) {
+		*out = true;
+		return true;
+	} else if (strcasecmp(string, "false") == 0 || strcmp(string, "0") == 0) {
+		*out = false;
+		return true;
+	}
+
+	return false;
+}
+
+bool parse_urgency(const char *string, enum mako_notification_urgency *out) {
+	if (strcasecmp(string, "low") == 0) {
+		*out = MAKO_NOTIFICATION_URGENCY_LOW;
+		return true;
+	} else if (strcasecmp(string, "normal") == 0) {
+		*out = MAKO_NOTIFICATION_URGENCY_NORMAL;
+		return true;
+	} else if (strcasecmp(string, "high") == 0) {
+		*out = MAKO_NOTIFICATION_URGENCY_HIGH;
+		return true;
+	}
+
+	return false;
+}
+
+bool parse_criteria(const char *string, struct mako_criteria *criteria) {
+	// Create space to build up the current token that we're reading. We know
+	// that no single token can ever exceed the length of the entire criteria
+	// string, so that's a safe length to use for the buffer.
+	int token_max_length = strlen(string) + 1;
+	char token[token_max_length];
+	memset(token, 0, token_max_length);
+	size_t token_location = 0;
+
+	enum mako_parse_state state = MAKO_PARSE_STATE_NORMAL;
+	const char *location = string;
+
+	char ch;
+	while ((ch = *location++) != '\0') {
+		switch (state) {
+		case MAKO_PARSE_STATE_ESCAPE:
+		case MAKO_PARSE_STATE_QUOTE_ESCAPE:
+			token[token_location] = ch;
+			++token_location;
+			state &= ~MAKO_PARSE_STATE_ESCAPE; // These work as a bitmask.
+			break;
+
+		case MAKO_PARSE_STATE_QUOTE:
+			switch (ch) {
+			case '\\':
+				state = MAKO_PARSE_STATE_QUOTE_ESCAPE;
+				break;
+			case '"':
+				state = MAKO_PARSE_STATE_NORMAL;
+				break;
+			case ' ':
+			default:
+				token[token_location] = ch;
+				++token_location;
+			}
+			break;
+
+		case MAKO_PARSE_STATE_NORMAL:
+			switch (ch) {
+			case '\\':
+				state = MAKO_PARSE_STATE_ESCAPE;
+				break;
+			case '"':
+				state = MAKO_PARSE_STATE_QUOTE;
+				break;
+			case ' ':
+				// New token, apply the old one and reset our state.
+				if (!apply_criteria_field(criteria, token)) {
+					// An error should have been printed already.
+					return false;
+				}
+				memset(token, 0, token_max_length);
+				token_location = 0;
+				break;
+			default:
+				token[token_location] = ch;
+				++token_location;
+			}
+			break;
+		}
+	}
+
+	if (state != MAKO_PARSE_STATE_NORMAL) {
+		if (state & MAKO_PARSE_STATE_QUOTE) {
+			fprintf(stderr, "Unmatched quote in criteria definition\n");
+			return false;
+		} else if (state & MAKO_PARSE_STATE_ESCAPE) {
+			fprintf(stderr, "Trailing backslash in criteria definition\n");
+			return false;
+		} else {
+			fprintf(stderr, "Got confused parsing criteria definition\n");
+			return false;
+		}
+	}
+
+	// Apply the last token, which will be left in the buffer after we hit the
+	// final NULL. We know it's valid since we just checked for that.
+	if (!apply_criteria_field(criteria, token)) {
+		// An error should have been printed by this point, we don't need to.
+		return false;
+	}
+
+	return true;
+}
+
+// Takes a token from the criteria string that looks like "key=value", figures
+// out which field of the criteria "key" refers to, and sets it to "value".
+// Any further equal signs are assumed to be part of the value. If there is no .
+// equal sign present, the field is treated as a boolean, with a leading
+// exclamation point signifying negation.
+//
+// Note that the token will be consumed.
+bool apply_criteria_field(struct mako_criteria *criteria, char *token) {
+	char *key = token;
+	char *value = strstr(key, "=");
+	bool bare_key = !value;
+
+	if (*key == '\0') {
+		return true;
+	}
+
+	if (value) {
+		// Skip past the equal sign to the value itself.
+		*value = '\0';
+		++value;
+	} else {
+		// If there's no value, assume it's a boolean, and set the value
+		// appropriately. This allows uniform parsing later on.
+		if (*key == '!') {
+			// Negated boolean, skip past the exclamation point.
+			++key;
+			value = "false";
+		} else {
+			value = "true";
+		}
+	}
+
+	// Now apply the value to the appropriate member of the criteria.
+	// If the value was omitted, only try to match against boolean fields.
+	// Otherwise, anything is fair game. This helps to return a better error
+	// message.
+
+	if (!bare_key) {
+		if (strcmp(key, "app-name") == 0) {
+			criteria->app_name = strdup(value);
+			criteria->spec.app_name = true;
+			return true;
+		} else if (strcmp(key, "app-icon") == 0) {
+			criteria->app_icon = strdup(value);
+			criteria->spec.app_icon = true;
+			return true;
+		} else if (strcmp(key, "urgency") == 0) {
+			if (!parse_urgency(value, &criteria->urgency)) {
+				fprintf(stderr, "Invalid urgency value '%s'", value);
+				return false;
+			}
+			criteria->spec.urgency = true;
+			return true;
+		} else if (strcmp(key, "category") == 0) {
+			criteria->category = strdup(value);
+			criteria->spec.category = true;
+			return true;
+		} else if (strcmp(key, "desktop-entry") == 0) {
+			criteria->desktop_entry = strdup(value);
+			criteria->spec.desktop_entry = true;
+			return true;
+		} else {
+			// Anything left must be one of the boolean fields, defined using
+			// standard syntax. Continue on.
+		}
+	}
+
+	if (strcmp(key, "actionable") == 0) {
+		if (!parse_boolean(value, &criteria->actionable)) {
+			fprintf(stderr, "Invalid value '%s' for boolean field '%s'\n",
+					value, key);
+			return false;
+		}
+		criteria->spec.actionable = true;
+		return true;
+	} else {
+		if (bare_key) {
+			fprintf(stderr, "Invalid boolean criteria field '%s'\n", key);
+		} else {
+			fprintf(stderr, "Invalid criteria field '%s'\n", key);
+		}
+		return false;
+	}
+
+	return true;
+}
+
+// Retreive the global critiera from a given mako_config. This just so happens
+// to be the first criteria in the list.
+struct mako_criteria *global_criteria(struct mako_config *config) {
+	struct mako_criteria *criteria =
+		wl_container_of(config->criteria.next, criteria, link);
+	return criteria;
+}
+
+
+// Iterate through `criteria_list`, applying the style from each matching
+// criteria to `notif`. Returns the number of criteria that matched, or -1 if
+// a failure occurs.
+ssize_t apply_each_criteria(struct wl_list *criteria_list,
+		struct mako_notification *notif) {
+	ssize_t match_count = 0;
+
+	struct mako_criteria *criteria;
+	wl_list_for_each(criteria, criteria_list, link) {
+		if (!match_criteria(criteria, notif)) {
+			continue;
+		}
+		++match_count;
+
+		if (!apply_style(&notif->style, &criteria->style)) {
+			return -1;
+		}
+	}
+
+	return match_count;
+}
diff --git a/dbus/xdg.c b/dbus/xdg.c
index 281c1d39..e5739a15 100644
--- a/dbus/xdg.c
+++ b/dbus/xdg.c
@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "criteria.h"
 #include "dbus.h"
 #include "mako.h"
 #include "notification.h"
@@ -27,21 +28,21 @@ static int handle_get_capabilities(sd_bus_message *msg, void *data,
 		return ret;
 	}
 
-	if (strstr(state->config.style.format, "%b") != NULL) {
+	if (strstr(global_criteria(&state->config)->style.format, "%b") != NULL) {
 		ret = sd_bus_message_append(reply, "s", "body");
 		if (ret < 0) {
 			return ret;
 		}
 	}
 
-	if (state->config.style.markup) {
+	if (global_criteria(&state->config)->style.markup) {
 		ret = sd_bus_message_append(reply, "s", "body-markup");
 		if (ret < 0) {
 			return ret;
 		}
 	}
 
-	if (state->config.style.actions) {
+	if (global_criteria(&state->config)->style.actions) {
 		ret = sd_bus_message_append(reply, "s", "actions");
 		if (ret < 0) {
 			return ret;
@@ -212,8 +213,22 @@ static int handle_notify(sd_bus_message *msg, void *data,
 		return ret;
 	}
 
-	if (expire_timeout < 0 || state->config.style.ignore_timeout) {
-		expire_timeout = state->config.style.default_timeout;
+	int match_count = apply_each_criteria(&state->config.criteria, notif);
+	if (match_count == -1) {
+		// We encountered an allocation failure or similar while applying
+		// criteria. The notification may be partially matched, but the worst
+		// case is that it has an empty style, so bail.
+		fprintf(stderr, "Failed to apply criteria\n");
+		return -1;
+	} else if (match_count == 0) {
+		// This should be impossible, since the global criteria is always
+		// present in a mako_config and matches everything.
+		fprintf(stderr, "Notification matched zero criteria?!\n");
+		return -1;
+	}
+
+	if (expire_timeout < 0 || notif->style.ignore_timeout) {
+		expire_timeout = notif->style.default_timeout;
 	}
 
 	insert_notification(state, notif);
diff --git a/include/config.h b/include/config.h
index c5bc4290..fbf9a389 100644
--- a/include/config.h
+++ b/include/config.h
@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <wayland-client.h>
 
 struct mako_directional {
 	int32_t top;
@@ -28,7 +29,7 @@ enum mako_sort_criteria {
 // structs are also mirrored.
 struct mako_style_spec {
 	bool width, height, margin, padding, border_size, font, markup, format,
-		 actions, default_timeout;
+		 actions, default_timeout, ignore_timeout;
 
 	struct {
 		bool background, text, border;
@@ -60,14 +61,15 @@ struct mako_style {
 };
 
 struct mako_config {
-	struct mako_style style;
+	struct wl_list criteria; // mako_criteria::link
 
 	int32_t max_visible;
 	char *output;
-	char *hidden_format;
 	uint32_t sort_criteria; //enum mako_sort_criteria
 	uint32_t sort_asc;
 
+	struct mako_style hidden_style;
+
 	struct {
 		enum mako_button_binding left, right, middle;
 	} button_bindings;
@@ -77,7 +79,9 @@ void init_default_config(struct mako_config *config);
 void finish_config(struct mako_config *config);
 
 void init_default_style(struct mako_style *style);
+void init_empty_style(struct mako_style *style);
 void finish_style(struct mako_style *style);
+bool apply_style(struct mako_style *target, const struct mako_style *style);
 
 int parse_config_arguments(struct mako_config *config, int argc, char **argv);
 int load_config_file(struct mako_config *config);
diff --git a/include/criteria.h b/include/criteria.h
new file mode 100644
index 00000000..8f0d8ae5
--- /dev/null
+++ b/include/criteria.h
@@ -0,0 +1,65 @@
+#ifndef _MAKO_CRITERIA_H
+#define _MAKO_CRITERIA_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "config.h"
+#include "notification.h"
+
+struct mako_config;
+
+// State is intended to work as a bitmask, so if more need to be added in the
+// future, this should be taken into account.
+enum mako_parse_state {
+	MAKO_PARSE_STATE_NORMAL = 0,
+	MAKO_PARSE_STATE_ESCAPE = 1,
+	MAKO_PARSE_STATE_QUOTE = 2,
+	MAKO_PARSE_STATE_QUOTE_ESCAPE = 3,
+};
+
+// Stores whether or not each field was part of the criteria specification, so
+// that, for example, "not actionable" can be distinguished from "don't care".
+// This is unnecessary for string fields, but it's best to just keep it
+// consistent.
+struct mako_criteria_spec {
+	bool app_name;
+	bool app_icon;
+	bool actionable;
+	bool urgency;
+	bool category;
+	bool desktop_entry;
+};
+
+struct mako_criteria {
+	struct mako_criteria_spec spec;
+	struct wl_list link; // mako_config::criteria
+
+	// Style to apply to matches:
+	struct mako_style style;
+
+	// Fields that can be matched:
+	char *app_name;
+	char *app_icon;
+	bool actionable; // Whether mako_notification.actions is nonempty
+
+	enum mako_notification_urgency urgency;
+	char *category;
+	char *desktop_entry;
+};
+
+struct mako_criteria *create_criteria(struct mako_config *config);
+void destroy_criteria(struct mako_criteria *criteria);
+bool match_criteria(struct mako_criteria *criteria,
+		struct mako_notification *notif);
+
+bool parse_boolean(const char *string, bool *out);
+bool parse_urgency(const char *string, enum mako_notification_urgency *out);
+
+bool parse_criteria(const char *string, struct mako_criteria *criteria);
+bool apply_criteria_field(struct mako_criteria *criteria, char *token);
+
+struct mako_criteria *global_criteria(struct mako_config *config);
+ssize_t apply_each_criteria(struct wl_list *criteria_list,
+		struct mako_notification *notif);
+
+#endif
diff --git a/include/notification.h b/include/notification.h
index 1bd3cb67..2296fa90 100644
--- a/include/notification.h
+++ b/include/notification.h
@@ -5,6 +5,8 @@
 #include <stdint.h>
 #include <wayland-client.h>
 
+#include "config.h"
+
 enum mako_notification_urgency {
 	MAKO_NOTIFICATION_URGENCY_LOW = 0,
 	MAKO_NOTIFICATION_URGENCY_NORMAL = 1,
@@ -24,6 +26,8 @@ struct mako_notification {
 	struct mako_state *state;
 	struct wl_list link; // mako_state::notifications
 
+	struct mako_style style;
+
 	uint32_t id;
 	char *app_name;
 	char *app_icon;
diff --git a/mako.1.scd b/mako.1.scd
index c9da007b..6586223e 100644
--- a/mako.1.scd
+++ b/mako.1.scd
@@ -19,6 +19,31 @@ dismissed with a click or via *makoctl*(1).
 *-h, --help*
 	Show help message and quit.
 
+# GLOBAL CONFIGURATION OPTIONS
+
+*--max-visible* _n_
+	Set maximum number of visible notifications to _n_. Older notifications will
+	be hidden. If -1, all notifications are visible.
+
+	Default: 5
+
+*--sort* _+/-time_ | _+/-priority_
+	Sorts incoming notifications by time and/or priority in ascending(+)
+	or descending(-) order.
+
+	Default: -time
+
+*--output* _name_
+	Show notifications on the specified output. If empty, notifications will
+	appear on the focused output.
+
+	Requires the compositor to support the Wayland protocol
+	xdg-output-unstable-v1 version 2.
+
+	Default: ""
+
+# STYLE OPTIONS
+
 *--font* _font_
 	Set font to _font_, in Pango format.
 
@@ -79,19 +104,6 @@ dismissed with a click or via *makoctl*(1).
 
 	Default: <b>%s</b>\\n%b
 
-*--max-visible* _n_
-	Set maximum number of visible notifications to _n_. Older notifications will
-	be hidden. If -1, all notifications are visible.
-
-	Default: 5
-
-*--sort* _+/-time_ | _+/-priority_
-	Sorts incoming notifications by time and/or priority in ascending(+)
-	or descending(-) order.
-
-	Default: -time
-
-
 *--default-timeout* _timeout_
 	Set the default timeout to _timeout_ in milliseconds. To disable the
 	timeout, set it to zero.
@@ -104,15 +116,6 @@ dismissed with a click or via *makoctl*(1).
 
 	Default: 0
 
-*--output* _name_
-	Show notifications on the specified output. If empty, notifications will
-	appear on the focused output.
-
-	Requires the compositor to support the Wayland protocol
-	xdg-output-unstable-v1 version 2.
-
-	Default: ""
-
 # CONFIG FILE
 
 The config file is located at *~/.config/mako/config* or at
@@ -124,11 +127,52 @@ Is equivalent to passing *--key=value* to mako from the command line.
 
 Empty lines and lines that begin with # are ignored.
 
-The hidden notifications placeholder can be configured after a *[hidden]*
-section:
+# CRITERIA
+
+In addition to the set of options at the top of the file, the config file may
+contain zero or more sections, each containing any combination of the
+*STYLE OPTIONS*. The sections, called criteria, are defined with an INI-like
+square bracket syntax. The brackets may contain any number of fields, like so:
+
+	\[field=value field2=value2 ...\]
+
+When a notification is received, it will be compared to the fields defined in
+each criteria. If all of the fields match, the style options within will be
+applied to the notification. Fields not included in the criteria are not
+considered during the match. A notification may match any number of criteria.
+This matching occurs in the order the criteria are defined in the config file,
+meaning that if multiple criteria match a notification, the last occurrence of
+any given style option will "win".
+
+The following fields are available in critiera:
+
+- _app-name_ (string)
+- _app-icon_ (string)
+- _urgency_ (one of "low", "normal", "high")
+- _category_ (string)
+- _desktop-entry_ (string)
+- _actionable_ (boolean)
+- _hidden_ (boolean)
+	- _hidden_ is special, it defines the style for the placeholder shown when
+	  the number of notifications exceeds _max-visible_.
+
+If a field's value contains special characters, they may be escaped with a
+backslash, or quoted:
+
+	\[app-name="Google Chrome"\]
+
+	\[app-name=Google\\ Chrome\]
+
+Quotes within quotes may also be escaped, and a literal backslack may be
+specified as \\\\. No spaces are allowed around the equal sign. Escaping equal
+signs within values is unnecessary.
+
+Additionally, boolean values may be specified using any of true/false, 0/1, or
+as bare words:
+
+	\[actionable=true\] \[actionable=1\] \[actionable\]
 
-	\[hidden\]
-	format=(%h more)
+	\[actionable=false\] \[actionable=0\] \[!actionable\]
 
 # COLORS
 
diff --git a/meson.build b/meson.build
index a65ecb4a..d163aa18 100644
--- a/meson.build
+++ b/meson.build
@@ -38,6 +38,7 @@ executable(
 		'pool-buffer.c',
 		'render.c',
 		'wayland.c',
+		'criteria.c',
 	]),
 	dependencies: [
 		cairo,
diff --git a/notification.c b/notification.c
index 92f1c120..50ce528f 100644
--- a/notification.c
+++ b/notification.c
@@ -10,6 +10,7 @@
 #include <dev/evdev/input-event-codes.h>
 #endif
 
+#include "config.h"
 #include "dbus.h"
 #include "event-loop.h"
 #include "mako.h"
@@ -49,6 +50,7 @@ void destroy_notification(struct mako_notification *notif) {
 		free(action);
 	}
 	destroy_timer(notif->timer);
+	finish_style(&notif->style);
 	free(notif->app_name);
 	free(notif->app_icon);
 	free(notif->summary);
@@ -212,7 +214,7 @@ size_t format_text(const char *format, char *buf, mako_format_func_t format_func
 		char *value = NULL;
 		bool markup = false;
 
-		if (current[1] == '%') { 
+		if (current[1] == '%') {
 			value = strdup("%");
 		} else {
 			value =	format_func(current[1], &markup, data);
diff --git a/render.c b/render.c
index f403df19..9da10e72 100644
--- a/render.c
+++ b/render.c
@@ -3,6 +3,8 @@
 #include <cairo/cairo.h>
 #include <pango/pangocairo.h>
 
+#include "config.h"
+#include "criteria.h"
 #include "mako.h"
 #include "notification.h"
 #include "render.h"
@@ -114,7 +116,6 @@ static int render_notification(cairo_t *cairo, struct mako_state *state,
 
 int render(struct mako_state *state, struct pool_buffer *buffer, int scale) {
 	struct mako_config *config = &state->config;
-	struct mako_style *style = &config->style;
 	cairo_t *cairo = buffer->cairo;
 
 	if (wl_list_empty(&state->notifications)) {
@@ -128,17 +129,17 @@ int render(struct mako_state *state, struct pool_buffer *buffer, int scale) {
 	cairo_paint(cairo);
 	cairo_restore(cairo);
 
-	int inner_margin = style->margin.top;
-	if (style->margin.bottom > style->margin.top) {
-		inner_margin = style->margin.bottom;
-	}
-
 	int notif_width = state->width;
 
 	size_t i = 0;
 	int total_height = 0;
+	int pending_bottom_margin = 0;
 	struct mako_notification *notif;
 	wl_list_for_each(notif, &state->notifications, link) {
+		// Note that by this point, everything in the style is guaranteed to
+		// be specified, so we don't need to check.
+		struct mako_style *style = &notif->style;
+
 		size_t text_len =
 			format_text(style->format, NULL, format_notif_text, notif);
 		char *text = malloc(text_len + 1);
@@ -148,7 +149,11 @@ int render(struct mako_state *state, struct pool_buffer *buffer, int scale) {
 		format_text(style->format, text, format_notif_text, notif);
 
 		if (i > 0) {
-			total_height += inner_margin;
+			if (style->margin.top > pending_bottom_margin) {
+				total_height += style->margin.top;
+			} else {
+				total_height += pending_bottom_margin;
+			}
 		}
 
 		int notif_height = render_notification(
@@ -162,6 +167,7 @@ int render(struct mako_state *state, struct pool_buffer *buffer, int scale) {
 		notif->hotspot.height = notif_height;
 
 		total_height += notif_height;
+		pending_bottom_margin = style->margin.bottom;
 
 		++i;
 		if (config->max_visible >= 0 &&
@@ -171,20 +177,33 @@ int render(struct mako_state *state, struct pool_buffer *buffer, int scale) {
 	}
 
 	if (wl_list_length(&state->notifications) > config->max_visible) {
-		total_height += inner_margin;
+		// Apply the hidden_style on top of the global style. This has to be
+		// done here since this notification isn't "real" and wasn't processed
+		// by apply_each_criteria.
+		struct mako_style style;
+		init_empty_style(&style);
+		apply_style(&style, &global_criteria(config)->style);
+		apply_style(&style, &config->hidden_style);
+
+		if (style.margin.top > pending_bottom_margin) {
+			total_height += style.margin.top;
+		} else {
+			total_height += pending_bottom_margin;
+		}
 
 		size_t text_ln =
-			format_text(config->hidden_format, NULL, format_state_text, state);
+			format_text(style.format, NULL, format_state_text, state);
 		char *text = malloc(text_ln + 1);
 		if (text == NULL) {
 			fprintf(stderr, "allocation failed");
 			return 0;
 		}
-		format_text(config->hidden_format, text, format_state_text, state);
+		format_text(style.format, text, format_state_text, state);
 
 		int hidden_height = render_notification(
-				cairo, state, style, text, total_height, scale);
+				cairo, state, &style, text, total_height, scale);
 		free(text);
+		finish_style(&style);
 
 		total_height += hidden_height;
 	}
diff --git a/wayland.c b/wayland.c
index 2a235c4c..699237e6 100644
--- a/wayland.c
+++ b/wayland.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "criteria.h"
 #include "mako.h"
 #include "notification.h"
 #include "render.h"
@@ -407,14 +408,15 @@ void send_frame(struct mako_state *state) {
 		zwlr_layer_surface_v1_add_listener(state->layer_surface,
 			&layer_surface_listener, state);
 
-		struct mako_config *config = &state->config;
-		zwlr_layer_surface_v1_set_size(state->layer_surface,
-			config->style.width, height);
+		struct mako_style *style = &global_criteria(&state->config)->style;
+
+		zwlr_layer_surface_v1_set_size(state->layer_surface, style->width,
+				height);
 		zwlr_layer_surface_v1_set_anchor(state->layer_surface,
 			ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT);
 		zwlr_layer_surface_v1_set_margin(state->layer_surface,
-			config->style.margin.top, config->style.margin.right,
-			config->style.margin.bottom, config->style.margin.left);
+			style->margin.top, style->margin.right,
+			style->margin.bottom, style->margin.left);
 		wl_surface_commit(state->surface);
 		return;
 	}
@@ -427,7 +429,7 @@ void send_frame(struct mako_state *state) {
 	// requested, we'll enter an infinite loop
 	if (state->height != height) {
 		zwlr_layer_surface_v1_set_size(state->layer_surface,
-			state->config.style.width, height);
+			global_criteria(&state->config)->style.width, height);
 		wl_surface_commit(state->surface);
 		return;
 	}