Clarifications around quotes in footnotes

[UnasZole]

Hi,

Reading the USFM documentation, I have several questions around quotes.

First question is : what is the semantic difference between fq and fk ?
The documentation says :

• fq : "A quotation from the current scripture text translation for which the note is being provided. "
• fk : "The specific keyword/term from the text for which the footnote is being provided."

In both case, it's the extract from the current scripture which the note applies to.
The only difference I understand from that text is that fk seems to allow only a single word whereas fq allows any quotation (be it a single word or a phrase) but that seems very arbitrary. In which case would it be correct to use \fk but wrong to use \fq , and reciprocally ?

Second question is : What quote elements are available in footnotes, and for which use case ?
In the documentation's "footnote content" elements section, the following are defined :

• fq: for the exact quote that the note applies to.
• fk: apparently same but for a single word
• fqa: for an alternate translation of that quote

What about quotes from other texts ? Is it valid to use \qt (possibly in a nested form +qt) within footnotes for this use case ?