These are UK/Australian abbreviations. The US terms are bracketed in italics.
Basic crochet abbreviations:
ch chain (see video tutorial)
sc single crochet (sl st slip stitch)
dc double crochet (sc single crochet)
htr half treble crochet (hdc half double crochet)
tr treble crochet (dc double crochet)
beg begin(ning)
cont continue
Lp(s) loop(s)
Patt pattern
rem remaining
rep repeat
Sl slip