[nsguy]

A lot of tabs do have them... Also you're not always picking notes from a chord, though I guess often you are.

[Ylpertnodi]

You always are [picking notes from a chord]...or purposely omitting them.

c e g b d f a = CMaj13.

Missing/ 'passing' notes -

c# g# d# f# a#.

[nsguy]

But that's not useful. So you're saying just put on a CMaj13 grip for playing anything in a scale to the OP? On your 7 string guitar?

EDIT: Also you have to be missing at least one note... CMaj7 had 4 notes + 13 ... c e g b + a (the 13th) so CMaj7/13 Add 4 ?

The OP (as I understand it) was wanting to be able to know what shape/grip to use for picking the relevant notes... I'm sure it can be done but you have to also find the position and reasonable shapes that fit the notes in the bar.