When I encounter an ERROR, WARNING, or NOTE in my SAS log that I don't understand, my first recourse is to ask my friend (we'll call him "Google") what it could mean. I copy the entire message (or at least 5 or 6 consecutive words from it) into the search box, surrounded by quotes, and see what literal matches come up.
Not all messages indicate a problem; some are meant to be informational. Yet sometimes I need a little help to understand what that information should mean to me. (Here's an example of one that I wouldn't have guessed on my own.)
On the support.sas.com blog, Renee features the top 10 DATA step messages that prompt customers to call SAS Technical Support.
It's a guest post from Kim Wilson in SAS Technical Support, who is an expert in the area. Kim presented a paper at SAS Global Forum 2011; the paper contains even more useful details.
And now, thanks to the magic of indexed content on the support site and my friend Google (or the search box on support.sas.com), Kim's paper is one of the useful links that will pop up when you search on one of those messages.