What does trtr mean in crochet?

British notation

“trtr” only exists in British notation. A US pattern writes “dtr” for this stitch.

Try it with a row from your pattern

Here is a row that uses it. Replace it with a row from your pattern: every abbreviation the reader knows is underlined, and its meaning shows on hover.

Row 5: ch 5 (counts as trtr), trtr in each st across, turn (20)