What actions rewrite .htaccess

A couple general questions… We have a Drupal 7 website with a small custom 3rd party api that passes blog posts from this site to a second website, based on a specific field value. (that happens to use a subdomain of the first – though it’s not on the same server)

There is, apparently, also a couple lines of code in the primary site’s .htaccess file. Occasionally it gets overwritten, even though we believe we’ve done nothing to overwrite that file. 

So what scenarios would modify that file? 

I imagine doing website version updates to newer versions for security, often have this affect. But are there any other scenarios. Nothing to do with modules, etc? I wouldn’t think so, but I just want to do a process of elimination. 

Also, I’m trying to suggest an alternative, because I feel they should’ve done a Drupal module instead of whatever they did. Is there something out there that exists, and can it sit on the recipient site instead of this primary site? The only possibility I can think of is Feeds Xpath, but I’ve never done much with it – and we’re getting ready to redesign for D8 in coming months.

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed