A standard naming convention evolved lo so many years ago (see Wikipedia entry). For the purposes of UkeGeeks follow this guide:

Flats

use a lower case b, as in Eb for “E-flat“. Why a “b”? the actual character isn’t available in most font sets.

Sharps

use the # (called “hash” or “pound” or “octothorpe” — I kid you not), as in F# for “F-sharp“

Major

this is the “default” or standard chord and requires no additional notes. Thus “A Major” is written A

Minor

lower case “m” as in Em

Dominant 7th

just add “7” D7

Minor 7th

lowercase “m” and “7” – “A Minor 7th” is Am7

Diminished

“dim” as in Cdim. Diminished are sometimes written with a superscripted “o” (or degree symbol): A° . Do not use the superscript, use “-dim” suffix.

Major 7th

here we need to differentiate from “dominant 7th” so we include “maj” as with “D Major 7th” Dmaj7

Major 6th

C6

Suspended 2nd

Asus2

Suspended 4th

Csus4

Augmented

Baug. You might find it written with a plus sign, as in B+. Do not use this format, use “-aug” suffix.

Slash

slash chords are still a mystery to me (read this) but I can write them: D/A