diff --git a/command-line-interface.md b/command-line-interface.md
index c0f8a2833..1a8385ae3 100644
--- a/command-line-interface.md
+++ b/command-line-interface.md
@@ -102,10 +102,45 @@ $ echo $?
 0
 ```
 
+### kill
+
+[Send a signal][kill] to the container process.
+
+* *Arguments*
+  * *`<ID>`* The container being signaled.
+* *Options*
+  * *`--signal <SIGNAL>`* The signal to send (defaults to `TERM`).
+    The runtime MUST support `TERM` and `KILL` signals with [the POSIX semantics][posix-signals].
+    The runtime MAY support additional signal names.
+    On platforms that support [POSIX signals][posix-signals], the runtime MUST implement this command using POSIX signals.
+    On platforms that do not support POSIX signals, the runtime MAY implement this command with alternative technology as long as `TERM` and `KILL` retain their POSIX semantics.
+    Runtime authors on non-POSIX platforms SHOULD submit documentation for their TERM implementation to this specificiation, so runtime callers can configure the container process to gracefully handle the signals.
+* *Standard streams:*
+  * *stdin:* The runtime MUST NOT attempt to read from its stdin.
+  * *stdout:* The runtime MAY print diagnostic messaged to stdout, and the format for those lines is not specified in this document.
+  * *stderr:* The runtime MAY print diagnostic messages to stderr, and the format for those lines is not specified in this document.
+* *Exit code:* Zero if the signal was successfully sent to the container process and non-zero on errors.
+  Successfully sent does not mean that the signal was successfully received or handled by the container process.
+
+#### Example
+
+```
+# in a bundle directory with a process ignores TERM
+$ funC start --id sleeper-1 &
+$ funC kill sleeper-1
+$ echo $?
+0
+$ funC kill --signal KILL sleeper-1
+$ echo $?
+0
+```
+
 [bundle]: bundle.md
+[kill.2]: http://man7.org/linux/man-pages/man2/kill.2.html
 [posix-encoding]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap06.html#tag_06_02
 [posix-lang]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_02
 [posix-locale-encoding]: http://www.unicode.org/reports/tr35/#Bundle_vs_Item_Lookup
+[posix-signals]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html#tag_13_42_03
 [runtime]: glossary.md#runtime
 [start]: runtime.md#start
 [state]: runtime.md#state