A diacritic – also diacritical mark, diacritical point, diacritical sign from ancient Greek διά ( dia, through) and κρίνω ( krinein, to separate) – is a glyph added to a letter, or basic glyph. The term derives from the Greek διακριτικός ( diakritikós, "distinguishing"). Diacritic is primarily an adjective, though sometimes used as a noun, whereas diacritical is only ever an adjective. Some diacritical marks, such as the acute ( ´ ) and grave ( `&thins..
Conversation threading is a feature used by many email clients, , , and in which the software aids the user by visually grouping messages with their replies. These groups are called a conversation, topic thread, or simply a thread. A discussion forum, e-mail client or news client is said to have a "conversation view", "threaded topics" or a "threaded mode" if messages can be grouped in this manner.