Take the following as truth: Terms such as yadda yadda yadda and blah blah blah have a special utility when the speaker's audience can accurately fill in the blanks--when the terms act not as synonyms for generic talk but as command keys, cued to circumstance, that can designate specific information.
Then the following statement: "Terms like yadda yadda yadda are completely useless." is true, false, or inconclusive?