I wonder if this video helps? It seems to follow a bit of the pattern rows.
About halfway down the page it defines Tr/rf although you're right, Becky that the best source is the pattern itself. It may have its own definition.
Tr/rf Front Post Triple/ Treble Crochet or Tr/rf (raised treble crochet at the front of fabric) = wrap the yarn around the hook, insert the hook from in front and from right to left around the stem of the appropriate stitch, and complete the stitch normally