There are many FReepers who keep “ping lists”. Such a list includes the Freeper names of those who might be interested in any information about a certain topic. The topics of interest can be wide and varied. There are “ping lists” for UFO’s, religion, global warming, earthquakes, etc. In this case, for Barack Obama’s birth certificate issues.
If an article is posted that the “pinger” thinks that those on his/her “ping list” might be interested, that article is called to their attention by including them on “post to” header.
You get on a ‘ping list’ by letting the ‘keeper’ know of your interest.
Thanks so much for the PING explanation. That was very helpful and much appreciated. Best!
Publius