Dimitry Yemanov wrote about the complete Firebird 2.5 reference and how will be structured

I’m starting working on the contents for the complete Firebird 2.5

Language Reference with a hope to have it completed this winter. All the

appropriate questions and issues will be posted here in order to keep

everybody in sync. The first thing to discuss would be the document

structure.

Here is what I have in mind:

http://www.firebirdsql.org/download/rabbits/dimitr/LangRef.html

It’s just a draft and any feedback is welcome.

The major difference from what we have now is that the syntax diagrams

(along with the detailed description of the every clause) is moved to

the appendix A.

The major chapters contain the introduction to the appropriate

statements and the information on how to apply them to the common usage

patters instead.