There are two types of written notation for Crochet stitches; U.S. terminology (used in America and Canada), and U.K./British terminology (used across Europe, India, Australia, and others). Schematic crochet symbols have a consistent meaning internationally.
While the craft yarn council regulates the standards for crochet terminology, abbreviations may still vary between patterns and designers.
Basic stitches Listed in order of height. Almost all other crochet stitches are variations of the basic stitches. PhotographSchematic U.S. term U.K. termAbbreviations (U.S./U.K) Turning chainNumber of turning chainschain stitchchN/AN/Aslip stitchslip stitch / single crochetslst/ssN/A0single crochetdouble crochetsc/dc1half double crochethalf treble crochethdc/htr2double crochettreble crochetdc/tr3triple/treble crochetdouble treble crochettr/dtr4double treble crochettriple/treble treble crochetdtr/ttr5
Increasing and decreasing stitches An increase stitch refers to two or more stitches worked into the same spot (stitch); adding to the total amount of stitches. The abbreviation inc is standard internationally.
A decrease stitch refers to one stitch worked across two or more spots (stitches); subtracting from the total amount of stitches. Internationally abbreviated as dec (decrease) or st2tog (stitch two together (i.e.: sc2tog). A decrease worked over three stitches is referred to as st3tog (stitch three together (i.e.: sc3tog))
To find the turning chain, refer to the corresponding base stitch in the table above. Increase stitches Photograph Schematic U.S. term U.K. term Abbreviationsorsingle crochet increasedouble crochet increase inc US: sc-inc UK: dc-inchalf double crochet increasehalf treble crochet increaseUS: hdc-inc UK: htr-incdouble crochet increasetreble crochet increaseUS: dc-inc UK: tr-inctriple crochet increase/treble crochet increasedouble treble crochet increaseUS: tr-inc UK: dtr-incdouble treble crochet increaseUS: dtr-inc UK:Decrease Stitchessingle crochet decrease/two single crochets togetherdec/sc-dec/sc2togthree single crochets togethersc3toghalf double crochet decrease/two half double crochets togetherhdc-dec/hdc2togthree half double crochets togetherhdc3togdouble crochet decrease/two double crochets togetherdc-dec/dc2togthree double crochets togetherdc3togtreble crochet decrease/two treble crochets togethertr-dec/tr2togthree treble crochets togethertr3togdouble treble crochet decrease/two double treble crochets togetherdtr-dec/dtr2togthree double treble crochets togetherdtr3tog
Other commonly abbreviated stitches Photograph Schematic TermAbbreviations Relevancy/Notes PatternBack Loops only / Front Loops onlyBLO / FLOInsert hook into either the front loop of a stitch or the back loop.(identical to regular sc-dec)Invisible decreaseinv-dec/decCommonly used in amigurumi, slightly less visible than a regular sc-decInsert hook into front loops of next 2 stitches, YO pull through 2 loops, YO pull through 2 loops. Front post stitchesFP[basic stitch here] (i.e.: FPsc, FPhdc)Commonly used to create ribbing patterns, shorter than its original basic stitchInsert hook in from the back of the gap and into the front of the next gap, with the post in front of the hook.Shell stitchPopcorn stitchpcCluster/Puff/Bobblecl/ps/puff/boClusterPicotp/picotCommonly used to create a lacy texture in bordersChain 3, YO pull through 2 loops, crochet a basic stitch on the next stitch.
See also List of knitting stitches Gauge (Textile Crafts) List of Yarns for Crochet and Knitting
References
Edie Eckman, The Crochet Answer Book, North Adams, Massachusetts: Storey Publishing, 2005.