If you want to get technical about the naming of chord symbols - suspension versus retardation, passing tone, etc. - then giving just two events...
We are often seeing 'sus4', where the ^3 is replaced by ^4, which then usually resolves to said ^3.
...is not enough information. That two factor description could be the last two stages of a suspension or it could be an appoggiatura or a neighbor tone, etc.
And this gets to the main problem, if it's a problem at all, of the chord symbol labels: the symbols only apply to the vertical stack of tones, not to the movement of those tones. Ex.
sus4 is applied when there is a root and a
P5 (and if it's sensible, no third) above the root, regardless of how you approached or departed the
I agree, it would make sense to use
ret2 instead of
sus2, if the movement of the tones was an actual retardation. But that is only one particular example of how the
sus label, in actual use, doesn't fit the technical definition of a suspension.
You could say something similar to
add chord labels and various
13 extension labels. Songbooks frequently use those labels on chords where the tones in question are clearly not chord extensions, but instead are various non-chord tones.
...maybe even sus3 might be more accurate - after all, it's that ^3 that's suspended.
This part seems beside the point, but it's so wrong that it should be addressed.
A suspension has three stages and the actual suspension is the middle event when a tone which had been a chord tone is held, meaning suspended from moving to a chord tone in the next chord.
In the example, it isn't the third of
I being suspended, but rather the seventh of
V7 is suspended.