This note proposed how comments and annotations in CASL can be defined such that widely available tools like flex/bison can be used to construct CASL lexers and context free parsers: annotations are divided into a set of standard annotations (which are represented in the context free grammar) and special purpose annotations with a uniform syntax.
Standard annotations are automatically recognized by parsers that implement the context free grammar because the annotations occur in the grammar.
Special purpose annotations can be handled similarly to comments by parsers in a uniform way: in the simplest case by ignoring them.
The note also described how the INKA frontend handles CASL input assuming the proposed scheme for handling comments and annotations.