What is an "unmentionable word" to SQL?

I am reading [sys.query_store_query_text (Transact-SQL)](https://docs.microsoft.com/en-us/sql/relational-databases/system-catalog-views/sys-query-store-query-text-transact-sql?view=sql-server-2017) and I see the following, so I google {SQL "unmentionable" word}

> has_restricted_text	

> bit	

> Query text contains a password or other unmentionable words.

Other then 3 links that take me back to where I found it, I don't find anything that appears to show a relationship to a password or anything that SQL might care about.