When we bind off a project, we should almost always bind off “in pattern.” That means that as we work our way across the bind-off row, we work each stitch as though we are working the current pattern row.
So if we are binding off on what is row three of the pattern, then we work each stitch as though we were actually working row three. We just happen to be binding off each stitch as we work it.
In ribbing, for example, we knit the knits and purl the purls as we bind off. But in seed stitch, we knit the purls and purl the knits.
(“Almost always” as long as the instructions don’t say otherwise. But note that many project instructions won’t tell you to bind off in pattern, even though the should.
Also, of course, binding off in pattern doesn’t apply if we’re doing something like a three-needle bind off.)