Polygonia comma form of comma is frequently confused with the dark form of the question mark ("P. interrogationis"), but the two can readily be distinguished by the shape of the comma mark on the underside. The pale form is easily confused with the satyr comma ("P. satyrus"), which usually occurs north and west of the eastern comma's range. They can be distinguished by the upperside color, which is orange brown in the comma and tawny yellowish brown in "P. satyrus"; by the underside pattern, which tends to be mottled in the comma but appears to be more longitudinally streaked in "P. satyrus";
Comma the full stops are frequently discarded. Punctuation has been added to many languages which originally developed without it, including a number of different comma forms. European languages like German, French, Italian, Spanish, and Portuguese use the same comma as English with similar spacing, though usage may be somewhat different. For instance, in Standard German, subordinate clauses are always preceded by commas. Modern Greek uses the same Unicode comma for its "kómma" () and it is officially romanized as a Latin comma, but it has additional roles owing to its conflation with the former hypodiastole, a curved interpunct used to disambiguate