diff --git a/sqlx-core/src/any/mod.rs b/sqlx-core/src/any/mod.rs
index 203223e0..084e8138 100644
--- a/sqlx-core/src/any/mod.rs
+++ b/sqlx-core/src/any/mod.rs
@@ -1,3 +1,5 @@
+//! Generic database driver with the specific driver selected at runtime.
+
 #[macro_use]
 mod decode;
 
diff --git a/sqlx-core/src/database.rs b/sqlx-core/src/database.rs
index b34d06a0..138aa6a8 100644
--- a/sqlx-core/src/database.rs
+++ b/sqlx-core/src/database.rs
@@ -1,4 +1,60 @@
-//! Traits to represent various database drivers.
+//! Traits to represent a database driver.
+//!
+//! # Support
+//!
+//! ## Tier 1
+//!
+//! Tier 1 support can be thought of as "guaranteed to work". Automated testing is setup to
+//! ensure a high level of stability and functionality.
+//!
+//! | Database | Version | Driver |
+//! | - | - | - |
+//! | [MariaDB] | 10.1+ | [`mysql`] |
+//! | [Microsoft SQL Server] | 2019 | [`mssql`] |
+//! | [MySQL] | 5.6, 5.7, 8.0 | [`mysql`] |
+//! | [PostgreSQL] | 9.5+ | [`postgres`] |
+//! | [SQLite] | 3.20.1+ | [`sqlite`] |
+//!
+//! [MariaDB]: https://mariadb.com/
+//! [MySQL]: https://www.mysql.com/
+//! [Microsoft SQL Server]: https://www.microsoft.com/en-us/sql-server
+//! [PostgreSQL]: https://www.postgresql.org/
+//! [SQLite]: https://www.sqlite.org/
+//!
+//! [`mysql`]: ../sqlite/index.html
+//! [`postgres`]: ../postgres/index.html
+//! [`mssql`]: ../mssql/index.html
+//! [`sqlite`]: ../sqlite/index.html
+//!
+//! ## Tier 2
+//!
+//! Tier 2 support can be thought as "should work". No specific automated testing is done,
+//! at this time, but there are efforts to ensure compatibility. Tier 2 support also includes
+//! database distributions that provide protocols that closely match a database from Tier 1.
+//!
+//! _No databases are in tier 2 at this time._
+//!
+//! # `Any`
+//!
+//! Selecting a database driver is, by default, a compile-time decision. SQLx is designed this way
+//! to take full advantage of the performance and type safety made available by Rust.
+//!
+//! We recognize that you may wish to make a runtime decision to decide the database driver. The
+//! [`Any`] driver is provided for that purpose.
+//!
+//! ## Example
+//!
+//! ```rust,ignore
+//! // connect to SQLite
+//! let conn = AnyConnection::connect("sqlite://file.db").await?;
+//!
+//! // connect to Postgres, no code change
+//! // required, decided by the scheme of the URI
+//! let conn = AnyConnection::connect("postgres://localhost/sqlx").await?;
+//! ```
+//!
+//! [`Any`]: ../any/index.html
+//!
 
 use std::fmt::Debug;
 
@@ -82,4 +138,7 @@ pub trait HasArguments<'q> {
     type ArgumentBuffer;
 }
 
+/// A [`Database`] that maintains a client-side cache of prepared statements.
+///
+/// [`Database`]: trait.Database.html
 pub trait HasStatementCache {}