Good question. The blazers/suits I have are all numeric sizes, but the non-blazer jackets (moto, field jacket, etc) I have are S-M-L. Maybe that's the distinction? Although now that I think of it, I have one nylon field/rain jacket that is numeric. I think all the online retailers have sales usually around January and July. Yoox gets old stock sporadically and is sometimes marked down a lot. I would definitely check out the Antwerp shop -- sale time or not.