Here's a quote from the article I've been studying:
3.2 - Suspended triads
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The thing to remember here is that the 3rd has been replaced
with another note - either the 2nd or the 4th.
So whereas with major and minor triads you have the 3rd to give
the 'flavour' of the chord (i.e major or minor), with suspended
triads you have no 3rd, so the chord is neither major nor
minor.
A suspended 4th triad would be : 1st 4th 5th
A suspended 2nd triad would be : 1st 2nd 5th
As with major and minor chords, you just double up on notes
to go from the triad to the chord.
BUT - you almost never double the 'suspended' note - you usually
only double the 1st or 5th.
So take Asus4 as our example.
Asus4 triad is : 1st 4th 5th = A D E
The shape is :
EADGBE
x02230
Asus4
dobro: anyway, I took an Am7 and dropped the third a semitone, hence my calling it Am7sus2.
I'm starting to get the feeling that chord names can be something of an interpretation sometimes, yeah?