The word “stitch” can refer to a few different kinds of structures in crochet. When these differences are relevant, I’ll refer to them using the following terms.

Substitch

A substitch is one of the basic steps used to construct all higher-level stitch forms. The main substitches are: insert hook, yarn over, and pull through.

Basic Stitch

A basic stitch is a series of substitches that forms one of the basic units of a pattern. In basic crochet, all of the basic stitches begin and end with 1 loop on the hook.

Superstitch

A superstitch is a series of basic stitches that forms a higher-level unit than a single stitch. This may span a single row, such as a shell or a segment of cable; or it may span multiple rows, as in star stitch.

Yarn Over (YO)

Yarn Over Hook (YOH)

Taking up an untwisted bight from the working yarn by wrapping it “over” the hook, so that the hook passes from the near side to the far side of the bight.

Yarn Under (YU)

Yarn Under Hook (YUH)

Reversed Yarn Over (RYO)

Taking up a twisted loop from the working yarn by wrapping it “under” the hook. This is the reverse of yarn over.

Insert Hook (IH)

Inserting the hook through the work at an anchor point from the near side to the far side. I will represent this as a form of loop on the hook, where the “loop” is the body of the work itself.

Pull Through (PT)

Pulling the topmost loop on the hook through the next topmost. Decreases the number of LOH by one.

Loop on Hook, Loops on Hook (LOH)

[…]

Anchor Point

[…]

Near Side (NS)

[…]

Far Side (FS)

[…]

Right Side (RS)

[…]

Wrong Side (WS)

[…]

Crochet patterns and charts are informal notational systems intended for human communication and interpretation. In particular, they are neither consistent nor precise enough for machine consumption or formal analysis. Therefore, I have adopted the following conventions consistently throughout this site, which I hope are rigorous without being too burdensome.

• Except where otherwise noted, stitches are referred to by US names.

• A space separates steps.

• Logical groups of steps are written in square brackets, whether or not they are repeated. For instance, attaching to the work is typically grouped as [ih yo pt].

• When any step or sequence of steps is repeated multiple times, the total number of repetitions is written after the repeated item. I have also chosen to typeset this as a superscript where possible, and otherwise use a caret/circumflex (^). Thus x1 is the same as x, x2 means [x x], x3 means [x x x], and so on, whatever x may be; and in general, xn or x^n means x … x(n times). This may include substitches, stitches, or bracketed groups of steps. Examples:

  ch2

  ch2

  ch 2

  dc2

  2dc

  dc in next 2 sts

  [sc hdc]10

  *1sc, 1hdc, rep from * 9 times

  *1sc, 1hdc*, rep from * to * 9 times

• Increases and decreases always spell out both the type of stitch and the pitch of the change, namely, the fraction n⁄d or ratio n:d between the number of stitches n being formed, and the number of stitches d being worked into.

  Most commonly this will be e.g. sc2⁄1 “single crochet two [stitches] over one [position]” (a basic increase) or sc1⁄2 “single crochet one [stitch] over two [positions]” (a basic decrease). Link to info about decreases.