There are two ways in which the morphological types can be written: either the Hubble class (sprials, ellipticals, etc), or as a numeric value between -6 and +11 (de Vaucouleurs). The correspondance between the two scales is detailed in the last column.
The Hubble morphological class is written in Simbad as essentially 2 parts:
The morphology:
elliptical E (E0...E9) -4...-3
spiral S (S0, Sa...Sd, Sm)
-2...+9
barred spiral SB (SB0, SBa...Sd, SBm)
-2...+9
irregular I +10...+11
The peculiarities: (before or after the
morphological class)
c compact -6(cE),
+11 (cI)
d dwarf -5(dE)
ringed r
open spiral s
peculiar p
The colon (:) indicates an uncertainty on the preceding symbol, e.g. S: means probably a Spiral, SB: means a spiral with a probable bar, and S:B: means probably a barred spiral.
In Simbad, two morphological classes may exist, separated by a slash, as E/S0 (elliptical or lenticular).