If they are partnering with one of your agencies, they should display agency's watermark.

There is a watermark, but it's not one I recognize.  No words; just the outline of a camera.

Thanks!  I'll give it a try. 

Thank you hatman12 and Jo Ann Snover.  Your responses are very helpful as well as really interesting.  I feel like I've descended into a rather dense culture with no available guidebooks    Getting some of the background makes this all just a bit less confounding.  Thanks!

Great!  Thanks for the info.

Thank you, chromaco.  I really appreciate your comments.
I do understand that the microstock business is no longer as promising or as comprehensible for photographers as it once was.  And that most questions that used to have fairly clear answers are now best responded to with "It depends."  And the "It" keeps changing too.  And it must be frustrating for pros to keep reading the same questions from new people over and over again. 
However, there will always be new people and the answers to those questions don't remain consistent.  I didn't take those 2 responses personally; but there must be other places for pros to vent their frustration.
As for my question:  perhaps I was trying too hard to seem "friendly."  I wanted to know how sites were applying Boolean logic to clients' keyword searches--the use of "and," "or," "not," etc.   From the responses here and what I've seen, it looks like lots of "and-ing" (or not  )
Again, thank you chromaco.  You gave me a much better sense of how crazy and crazy-making this has gotten.  After several weeks of editing my ten photos for SS and reading advice here and elsewhere, I uploaded them today.  At the very least, I've upped the technical expectations I have for my own work.  That's worth the time and effort.  Anything I hear from SS will just add to my learning curve. 

Seriously?  This is the supposed to be where new people introduce themselves and ask what might appear to be stupid questions. Apparently my attempt at humor with the sending photos on my computer out to earn money comment was taken seriously. Seriously?  I knew nothing about anyone's tag line and it has nothing to do with answering my question.

Hello All.  I'm new here and new to microstock.  Years ago I shot black and white film (mostly dancers and some street-shooting) and for the last 8 years or so I've been shooting digital color (mostly nature).  My images tend to live on my computer, so now I'm thinking of sending them out to earn their keep--or at least the occasional snack and maybe a new lens.
My keywording question is probably stupid, but I haven't been able to find an answer yet.  Do the stock stites' search tools look for individual words or do they also hunt for phrases?  For instance, if I am including the full name of a flower, do I put in each individual word separated by commas, or do I put in the full name, no commas?  If the main object is purple, do I just use the word purple or do I ALSO include purple bicycle?  Hope this makes sense.
I'm looking forward to learning a lot on this forum.  Thanks in advance!