Is there a custom of distributing a key description with databases, like it is done with maps?

For a project with a more complicated relational database structure, one of the requirements is long-term stability of the SQL database. To achieve this, I did some searching for a standard way of describing certain paths through a relational database. For example, this would include a description on how to combine related tables or a hierarchy of the keys/IDs used in the database.

What I am trying to do is a description of the database, so that someone who just imports the database dump to a SQL server will know how what queries to write and what fields to use as keys. (This situation could arise if, for example, the software used with the database can no longer be run at some point in time.)

While I am aware this could be done with UML, I'd like to ask whether there is some sort of standard or custom of distributing databases in open source software with a description, like the key always printed on maps so that people know what each color and line type means. Thanks!

via Chebli Mohamed