I'm currently working on the XML-RPC event plugin. One thing I noticed is that the dev docs could be improved. There are certainly more measures to improve but the top of the list would be to document data types of parameters and return values as well as the database values.
For example: https://docs.s9y.org/docs/developers/database.html describes the database fields. In serendipity_entries the column isdraft is described as
but during development I noticed it's not really boolean but a string representing a boolean value. Basically, it's (string) "true|false".Boolean to indicate if entry is a draft
I'd like to help improve the docs but what's the proper way? Adding PHPDoc blocks everywhere? Those are missing, too, sometimes, or lack the variable names in the @param clause. The docs' website could be improved, too, by documenting the API with the docblocks. I believe, this could be at least partially automated.