I don't think there is a real 4c category....cNapps are actually 4B...the "c" stands for "Cloud" or "Cotton" napps
cNapps (4B's) do not all look the same due to varying density & thickness levels however the similarities are mainly the fact that we have coils that do not clump and are not well defined like 4A's...
You can really tell the difference when the hair is wet or dried in a completely unmanipulated shrunken state b/c most 4A's & 4B's resemble each other when picked out into a fro depending on density levels , also 4B's can easily manipulate our napps to "appear" like we have coil definiton by doing braid outs and twist-outs......