Think about it. How many other articles are likely to have those keywords?
The original purpose of keywords was to allow anyone to search for articles that had those keywords. If everyone adds keywords that are only meaningful to them, that's not helpful to the next guy.
Other than no profanity or personal attacks, ther are no real 'acceptable' keywords. Use words that you think might be helpful in finding the article by someone doing a search on an appropriate keyword
That's how a few of us find threads for and from our ping lists - ex: MALKIN, PROLIFE, etc. :) It's VERY valuable IMHO!
Quite a number of them!