Is this actually worth documenting? 2.2.0 was released in 2005, 2.2.7 was never released. The flag has been available for over 8 years.

I left this open because I think the information in the description is useful for us in eventually crafting setup checks and possibly including in the documentation.

For example, T2226 discusses doing a webserver self-check for gzip, and merges T5067 to test for a missing "B" flag. I'm not sure what the behavior of apache is if you have a very old version and add "B", but if it's "run, but not work", having documentation about the minimum version here lets us tailor the error message for the "B" check when we write it (e.g., test the apache version, add a "You need to upgrade apache to version X" line if it's too old). I think these checks are helpful.

In general, I think we should accommodate very old versions of supporting software when we reasonably can. A lot of linux distros are years behind the cutting edge and I'd guess you can find multiple LTS releases today that give you something older-than-2.2.7 when you use the system package manager to install things. When we can't, we should try to proactively detect these versions and tell the user. Longer support windows and proactive version checks are usually easy for us to write and cheap to maintain, and they're unambiguous for users and probably pay for themselves in support costs.

Overall, I would expect this to end up in setup checks rather than documentation if at all possible (it is dramatically better for us to tell users "Your Apache is too old, upgrade to X" than to put a note in the docs which will often go unread), but the task description seemed possibly helpful in writing those checks.