Reference

US vs UK Crochet Terms

The single most common source of confusion in crochet: the same stitch name means a different stitch height depending on which side of the Atlantic the pattern was written on. Always check which convention a pattern uses before you start — this table converts between the two.

US TermUK Term
Slip stitch (sl st)Slip stitch (sl st)
Single crochet (sc)Double crochet (dc)
Half double crochet (hdc)Half treble crochet (htr)
Double crochet (dc)Treble crochet (tr)
Treble crochet (tr)Double treble crochet (dtr)
Double treble crochet (dtr)Triple treble crochet (trtr)
Skip (sk)Miss (miss)
GaugeTension
Yarn over (yo)Yarn over hook (yoh)

Notice the pattern: every US stitch name is one step "shorter" than its UK equivalent for the same actual stitch height. A pattern that never defines its terms but uses "treble crochet" as the shortest stitch is almost certainly UK-written; if "double crochet" is the shortest stitch, it's almost certainly US-written. This library uses US terms throughout.