What does this mean?

Hi

I’ve just started a new pattern for a cardigan and it reads: Back. Cast on 55 STS using 4 1/2 needles and M.

Work in g st until back measures 21cm.

What does the ‘M’ mean please?

Thanks

Welcome to KnittingHelp!
Does your pattern have multiple colors? Perhaps M is Main Color?

Oh yes it does!!! Oh thanks! I feel like such a doofus! :joy:

Usually you’d see MC for Main Color. I think that might have thrown me for a loop.

I was trying to remember if M was a crochet hook size.

I’ve never seen one that I recall but it seems there is an M hook.
http://www.yarnfwd.com/crochetconv.html