a	Orange filter used on SOHO spacecraft with C2 and C3 coronagraphs
A	Pogson
b	VBM method using RCA #4549 image intensifier
B	Simple Out-Out method
c	Unfiltered nuclear CCD magnitude
C	Unfiltered total CCD magnitude
d	Astrodon G filter
D	Johnson/Bessel/Kron/Cousins B with CCD
e	Extrafocal-Extinction (or Beyer) method using RCA #4549 image intensifier
E	Extrafocal-Extinction method
f	"Nuclear" magnitude obtained using Meade CCD interference filter CM-500 Visible
F	Total magnitude obtained using Meade CCD interference filter CM-500 Visible
g	CCD magnitude with Gunn g filter
G	CCD magnitude with a Corion NR-400 "minus-infrared" filter
H	Kron/Cousins I with CCD
i	Visual observation using an image intensifier
I	In-focus
j	Kron-Cousins V filter employed (m2 estimate)
J	Kron-Cousins V filter employed
k	Kron/Cousins R with CCD
K	Clear filter used on SOHO spacecraft with C3 coronagraph
l	CCD magnitude with a Wratten 25 filter
L	Photoelectric B
M	Modified-Out method
N	Called magnitude of nucleus or condensation
o	Visual extrafocal comparison using RCA #4549 image intensifier
O	Out-of-focus (or extrafocal) method
p	Photographic with Kodak 2415 film
P	photographic
q	R-band magnitude for nuclear condensation
Q	"out-out";  supposed to be same as VBB method
r	CCD magnitude with Gunn r filter
R	Photoelectric R
s	VSS method using image intensifier
S	In-Out method
t	Total visual magnitude (no other information provided;  historical obs. only)
T	Magnitude estimated from a TV monitor
u	CCD-derived V nuclear magnitudes (m2)
U	Johnson/Bessel/Kron/Cousins U with CCD
v	Photoelectric with filters to match visual
V	Johnson/Bessel/Kron/Cousins V with CCD
w	1P21 photometer + Kodak W64 filter
W	Photoelectric (no band given)
X	Ortochromatic film + yellow filter, which is a system very close to the V band
Y	Wratten No. 15 with CCD
Z	CCD Visual equivalent

