The reason why I titled this "Four Pieces" is because I wanted to use the words "Four" and the words "Pieces". I didn't want to use the number. I understand that IMSLP strives for conformity with regards to the titling of work pages (in terms of opus number format, syntax, capitalisation etc), but this particular composition is ONE piece, called "Four Pieces", with four separate movements. It's just *called* Four Pieces, it's not that it IS four distinct separate pieces (it is ONE composition).
In other compositions of mine where the number indicates the amount of pieces in the collection of pieces (e.g. 2 Origami) I've left it numbered.