harp gliss notation question

[MichelRE]

I can't seem to find the answer to this in Gould's book, so...

I notate a harp glissando.
Starting note... then 6 grace-note sized notes to show the required string tunings.
That's all fine.
It's even fine when the glissando is, for example, two hands in3rds, or 5ths...

The problem arises when in octaves!
Do I only write the 6 extra notes in one starting octave of that gliss?
Or repeat it for both starting octaves?

If I do only one octave, then the glissando lines are bizarrely skewered and not parallel.
If I do both octaves, it looks like overkill. But the gliss lines look good at least.

[David Ward]

My choice would be to notate both starting octaves in full; but I don't know whether or not that is officially correct.

[MichelRE]

my assumption as well, David.

fingers crossed that it is officially correct.
I haven't found a reference for it yet, but will keep searching.

[MichelRE]

well, right or wrong, I've decided to follow Piston's advice for my harp notation: pedal changes marked, and for glissandi, only starting and ending notes. I won't include the 6 notes of scale to indicate tuning (since tuning is already shown with pedal changes)

including the scale becomes too much of a hassle where there are multiple short (under 2 octaves) glissandi and space is limited.