Diminished chords
From Guitare Jazz Manouche Wiki
There are three basic positions for these chords also very widely used in many standards.
Root on the lower E string (Adim here) mostly played with the root between F# and C:
Root on the A string (Ddim here) mostly played with the root between B and F with the index muting the lower E string:
Root on the A string (Ddim here) mostly played with the root between B and F with the index muting the lower E string: