How can I report a user that abusively self-promotes their own company?

Question

There is a user on Stack Overflow that clearly self-promotes their own company.

This behavior includes:

1. Editing the questions of other users in order to add a new tag, and the text of the tag equals the text of their company.
2. Answering a question loosely related to their company by sponsoring their company (for e.g. answering a question about ML by sponsoring their own library, even when their own library doesn't allow to perform that specific ML task answered in the question).

How can I report this?

Answer 1

Where you see them:

Answering a question loosely related to his company by sponsoring his company (for e.g. answering a question about ML by sponsoring his own library, even when his own library doesn't allow to perform that specific ML task answered in the question).

I think you should flag the post using the "in need of moderator attention" option, and then describe what you think is astray with that post, and include mention of one or more places where you have seen them effectively editing in their own product as a tag.

Answer 2

You can flag an answer as spam:

Exists only to promote a product or service, does not disclose the author's affiliation.

The link gives some scope on what is acceptable.

Don't talk about your product / website / book / job too much. [...]

Don't tell - show! The best way to avoid being seen as a snake-oil salesman is to demonstrate a solution rather than simply asserting the problem can be solved.

Don't include links except to support what you've written.

Sounds like this person is failing all three criteria, so I would mark it as spam.