Currently I'm working on a tool to manipulate metadata in Firefox's cache2 cache-files. Since I did not find a source on the file format used that is either up-to-date or complete I worked my way through the source code for an "official" documentation of the format. My program is able to read the metadata successfully but when changing some data Firefox does accept the file anymore. It seems like I'm missing something but so far I'm not seeing it in the code. So my question is, is there some sort of documentation available besides the source code or is it possible to ask a developer, if there is somewhere something where the integrity of the file is checked? Thank you in advance for an answer.