all the internal tools and acronyms that are not explained anywhere
YMMV, but comments are not usually the best place for this kind of background information as you have to FIND the source file they're in before you can read them. Many teams will keep an external "glossary" of common acronyms and tools in an external data store (wiki / Confluence / etc). If your company doesn't have one, consider _starting_ one as you already need to ask what all those things are anyways and can collect the answers.Also consider if there's a better alternative to comments within your language's tooling - for instance, many languages now support generating human-readable documentation from metadata in source files (JavaDoc, ex_doc, YARD, etc)
Now, it would be good for you to understand if there's a rationale behind this (which would still be a major red flag), or if it's only a loose practice no one tried/succeeded to change.