… or extra switches requests it → … or extra switches request it
--- In the long run, if caNv is deemed useful, it could be suggested for inclusion into the PNG standard with a well-defined, well-specified, and standalone semantics so that other tools, such as GIMP, can handle it properly in all kinds of image processing (e.g., drop the chunk from the file when it stops making sense). If caNv can't be formalized properly in a standalone way, the chunk should be forgotten forever.
