I often use modified Helmholtz notation (MHN for short) as shorthand in Wikipedia talk pages.
MHN is just Helmholtz Pitch Notation but with the ASCII single quote used instead of the prime and subprime symbols. So in MHN, standard guitar tuning is E-A-d-g-b-e' while standard double bass tuning is E'-A'-D-G.
When typed on a QWERTY keyboard, MHN is more convenient than any of the other variants of Helmholtz notation, but it's similarly unambiguous and the differences between it and the original are purely cosmetic. I think I may have invented it independently, but it's such an obvious way to type Helmholtz Pitch Notation that even whether invented is the right word is questionable. I keep running across other websites that use it, and would welcome pointers to others I've missed so they can be added to my list!
See my page at http://tunings.pbworks.com/modified-Helmholtz-notation (which is part of The Online Encyclopedia Of Tunings or TOEOT for short) for a fuller description of MHN and links to some other sites that use it.
But while I use MHN exclusively at TOEOT and often in discussions here at Wikipedia, and obviously see some advantages to using it, IMO there's no chance of its adoption here at Wikipedia for use in articles. See Wikipedia:Manual of Style (music) and Wikipedia:Manual of Style (Stringed instrument tunings) for the styles that should be adopted in Wikipedia articles.
Of course, I could be wrong about that. But if you wish to use MHN in articles, my strong advice is that the talk pages of these MOS pages would be a good place to fly the idea first.