A few times recently, I've seen what looked like a slip-up by a poster (from context, the opposite of what it looked like they meant to say, or the non-obfuscated form of a name being used for one instance). If I accidentally did something like that, I'd appreciate being informed so I could edit my post to fix it.
What is the generally-accepted CS etiquette in a case like this:
1) Ignore it (if it's a mistake, it stays around for everyone to see)
2) Send a PM alerting them to a possible typo (nobody else sees the alert, avoids potential embarrassment)
3) Reply, alerting them to a possible typo (everyone sees the alert, high potential for embarrassment)
For the 2 cases I've seen recently, I took option #2 (the one I'd prefer if I made such a mistake), although in one case I later saw that someone else had taken option #3.