While learning to crochet, it occurred to me that crochet stitches (meaning the individual stitches rather than a pattern) can be complicated, they are made of a fairly limited selection of sub-operations. Also, though crochet patterns are easy to find online, the full breadth of possible stitches is trickier. As a result, I started to maintain my own list, which I present here now.
Below is an expandable list of a large number of crochet stitches, which links to diagrams and textual descriptions of how to make them further down this page. This list is not intended to be a crochet tutorial. The idea here is to inspire use of stitches beyond the small collection usually encountered.
The sub-operations can be summarised quite quickly: yarns over and under; picking up stitches (loops) by inserting the hook into various parts of the fabric; and drawing a loop from the tip of the hook under one or more of the other loops already on the hook. For most stitches, these operations suffice to describe the stitch. Unless otherwise stated, description starts with one loop on the hook, following an earlier stitch.
Expandable list of stitches
It's possible to categorise many standard stitches in a simple numerical way, (e.g. 1-2 for single crochet), to represent the numbers of loops pulled through loops at each stage of the stitch. To get the number of yarnovers required before each stitch, take the sum of each number minus one (e.g. 0-1), and further subtract one (e.g. 0). These are indexed below for completeness.