Why does the wiki page on coal say that coal has a flammability of 0 even though coal always lits on fire if in contact with it, no matter how high its life is?
The wiki has raw properties for each element, and generates the infobox using that. COAL burns in a special way, that the infobox can't see. That's why it burns so slowly.
An asterisk might be nice, if possible. But it is technically correct.