I just remembered a canon example from ST5. Only partially used in the film, but from Okrand's notes:

vubpu' jonta' HeSwI'. wa' vub ghaH tlhIngan gharwI''e'. wa' ghaH tera'ngan'e'.

I don't have the translation at hand, I'd say this would use a colon in English:

"Hostages have been taken: One Klingon diplomat and one Terran."

There are also examples from Star Trek III:

matHa' DoS jonta' neH
Gunner: target engine only.

Ignore the subtitle. I would punctuate this as follows: matHa', DoS: jonta' neH. Gunner [comma for direct address] the target [colon for a following explanation] engine only.

jabbI'ID pItlh
Transmission completed.

Again, ignore the subtitle. I would punctuate this as jabbI'ID: pItlh Data transmission [colon for a following description] finished.

The Klingon in Star Trek III is also a warning to us not to rely on formal grammar when in tense situations.

-- 
SuStel
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