I'm hoping for clarification on some fantasy-based terminology. I've read a number of websites that refer both to "orcs" and"orks", occasionally in the same sentence! Previously, I had only ever seen the term "orc" in fantasy writing.
From what limited information on the topic I've been able to find, "orks" seems to be a term for an orc-like creature in the Warhammer 40K series.
What I want to know is does the term "ork" apply exclusively to the character in the Warhammer 40K universe or does it also represent something else? Can "ork" and "orc" be used interchangeably? If does only apply to Warhammer, should it be considered a proper noun and capitalized at all times?