Where is the documentation for the ACL module/api? Has anyone successfully created a client module that controls node access via the ACL module? I installed this module and created my own UIs to populate the three tables: acl, acl_node and acl_user. I started to create nodes, which populated acl_node with appropriate values, but nothing else seemed to happen. No new realm in the node-access table, nothing. Have I missed a step? I can't find any documentation on this module/api. Thanks.

The notes in the nodes_access_example module (part of the examples project) encourage you to 'read up' on the ACL module. I can't find anything to read though.
If you take a look at the ACL project page, you'll see that the following four client modules exist:


Content Access
Flexi Access 
Forum Access
Image Gallery Access


You'll find plenty of examples on how to use the API in the source code of those.

The documentation for ACL are the comments embedded inside acl.module.  They are quite helpful when you try to create a client module.

P.S.: I am the maintainer of Flexi Access.  I can verify that ACL works as advertised.