TechCom is the owner of the Wikimedia development policy which includes several other items.
It'd be really good if TechCom could get into the habit of sending a regular (maybe every six months?) reminder to Wikitech-l welcoming new contributors and with an easy entry level about the current state of things.
Possible things to mention:
- Conduct – "Everyone involved in Wikimedia software development is required to follow our Code of Conduct. If you cannot or will not follow the Code, you are not welcome here."
- Security – "As a Wikimedia developer, you have a responsibility to write secure code in a style that is easy to review and audit. You must follow the security guidance and be aware of changes in the environment."
- Deprecation and backwards-compatibility – "All developers of Wikimedia software should follow the deprecation process unless there are exceptional reasons not so to do. Third party users of our software are important stakeholders, and their needs should be respected. Some areas, such as the APIs, have different approaches and public commitments to backwards-compatibility, and you should take that into account."
- Wikimedia deployment – "If your code is going to reach Wikimedia production, whether in MediaWiki core, an extension, as a config change, or via some other mechanism, you have a duty to be aware of the Wikimedia deployment concerns."
- Coding conventions – "Your code should always try to follow the appropriate coding conventions for its language and circumstance. Consistency between projects means production issues, performance concerns, and urgent tasks can be dealt with quickly and easily by as large a team as possible."
- Architectural compliance – "You should always build, maintain, and update code to be in line with the existing architecture of MediaWiki, or, if you see a good reason to change this, through the Requests for Comment process."
- It might be good to set out some long-term architectural changes happening, like getting MediaWiki and extension code ready for PHP7, replacing configuration with static json files, moving the front-end slowly to MVC based on OOjs UI, support for multi-data centre operation of MediaWiki, moving towards dependency injection, ….
This wouldn't replace good documentation on e.g. https://www.mediawiki.org/wiki/How_to_become_a_MediaWiki_hacker but visibility is always good to highlight.