Lower level HANDICAP races, commonly known as "Starter Handicap" races, are generally run as a series of races.
Today's 7th race at PARX was the first in a starter handicap series.
Think of a handicap race as a party. The racing secretary sends out invitations to the party and it is up to the recipient to accept or decline the invitation.
Below is a list of the horses that were invited to today's party.
The above is from the "condition book". Notice that is says the race "is to be run" (indicating at some future date) on May 28, 2013.
There were 39 horses invited. 12 of those 39 actually attended. Take note that the list is in "weight" order, with the high weight at the top and the low weight at the bottom. Also notice that the racing secretary "prefers" the high weighted horses attend. This is the way it works at ALL LEVELS.
As you can see, this is the first leg in the series, so there will be more to come. The dates and all other information is contained in the condition book and the horses connections are aware of when ALL legs in the series will be run.