diff --git a/Cargo.toml b/Cargo.toml
index aeb3c8a..c2c93c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ name = "license-exprs"
 version = "1.3.0"
 authors = ["Without Boats <woboats@gmail.com>"]
 license = "Apache-2.0 OR MIT"
-description = "Validate SPDX 2.1 license expressions."
+description = "Validate SPDX 2.1 license expressions using SPDX License List 3.0 identifiers."
 repository = "https://github.com/withoutboats/license-exprs"
 
 [[example]]
diff --git a/README.md b/README.md
index 987e889..555cffd 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,17 @@
-This crate validates license strings as [SPDX 2.1 license expressions](https://spdx.org/spdx-specification-21-web-version#h.jxpfx0ykyb60).
+# license-exprs
+
+This crate validates [SPDX 2.1 license expressions][SPDX-license-expressions] using short identifiers from the [SPDX 3.0 License List][SPDX-license-list].
+
+## Limitations
+
+Parentheses are [not currently supported][parens].
+
+## License
+
+Licensed under the [Apache License, Version 2.0][Apache-2.0] ([`LICENSE-APACHE`](LICENSE-APACHE)) or the [MIT license][MIT] ([`LICENSE-MIT`](LICENSE-MIT)), at your option.
+
+[Apache-2.0]: https://www.apache.org/licenses/LICENSE-2.0
+[MIT]: https://opensource.org/licenses/MIT
+[parens]: https://github.com/rust-lang-nursery/license-exprs/issues/3
+[SPDX-license-expressions]: https://spdx.org/spdx-specification-21-web-version#h.jxpfx0ykyb60
+[SPDX-license-list]: https://github.com/spdx/license-list-data/tree/v3.0