In Reply to: G-d?! Why not GOD? posted by Joshua on June 12, 2003 at 06:36:55:
It's a Jewish thing. The Hebrew letter has consonants, no vowels, so his name YAHWEH is spelled YHWH. The Jews consider the name of God too sacred to pronounce so don't even fill in the vowels and say Yahweh. Whenever they read the Hebrew word YHWH they pronounce it "Adonai" (Lord)instead.
It's a common Jewish note of respect for God to not put the vowel in even when saying "God" in English. You will often see Jewish people writing about "G-d".
Non-Jews may have copied this custom for their own reasons, but this is where it started.