These variable types are present in the AAVSO Validation File (program star
list).  The type descriptions given here are very simple. Complete descriptions
of variable star types may be found in the General Catalogue of Variable Stars,
4th edition.

Qualifiers
  : - uncertain
  / - and, based on classification simultaneously by components, shape of
      light curve, and degree of filling of Roche lobes
  + - variable belongs to more than one type simultaneously
Types
* - unique; outside range of classification system
? - unstudied
ACV - alpha CVn type rotating variable, strong magnetic field
ACYG - alpha Cyg type pulsating variable
AGN - active galactic nucleus; optically variable quasi-stellar extragalactic
      object [GCVS uses GAL]
AM - AM Her (magnetic) eruptive variable (polar variable)
BCEP - beta Cep type pulsating variable
BLLAC - extragalactic BL Lac type object
BY - BY Dra type rotating variable
CEP - Cepheid type pulsating variable
    CEP(B) - displaying two or more simultaneously operating pulsation modes
    CWA - W Vir type with period > 8 days
    CWB - W Vir type with period < 8 days
    DCEP - delta Cep type; classical Cepheid
         DCEPS - light amplitude < 0.5 magnitude
CST - non-variable (constant) star, formerly suspected of variability
CV - cataclysmic (eruptive) variable
DSCT - delta Sct type pulsating variable
E - eclipsing binary system
  EA - Algol (beta Per) type
  EB - beta Lyr type
  EW - W UMa type
ELL - ellipsoidal rotating variable
DM - detached close binary eclipsing system
KW - W UMa type contact close binary eclipsing system
FU - FU Ori type eruptive irregular Orion variable
GCAS - gamma Cas type eruptive irregular variable
GRB - gamma ray burster
GS - system with giant and/or supergiant component(s)
I - irregular, poorly studied, unknown features
IA - irregular, poorly studied, early spectral type
IB - irregular, poorly studied, intermediate-late spectral type
IN - Orion variable; irregular eruptive connected with diffuse nebulosity
   INA - early spectral type, Algol-like fading
   INB - intermediate-late spectral type, flares or Algol-like fading
   INS - rapid light changes observed
      INSA - early spectral type
      INSB - intermediate-late spectral type
      INST - T Tau type
   INT - T Tau type
IS - rapid irregular variable, no apparent connection with diffuse nebulosity
   ISA - early spectral type
   ISB - intermediate-late spectral type
   IST - T Tau type
L - irregular; periodicity absent, poorly defined, or insufficiently studied
LB - slow, irregular late spectral type variables; also, slow red irregular
     variables of unknown spectral type
LC - irregular variable late spectral type supergiants
M - Mira type (long period) pulsating variable
N - nova type eruptive system
  NA - fast rate of fading
  NB - slow rate of fading
  NC - remain at maximum light for 10+ years, very slow rate of fading
  NL - novalike
  NR - recurrent nova
PN - close binary system including nucleus of planetary nebula
PVTEL - PV Tel type pulsating variable
QSO - quasi-stellar object (quasar)
R - close binary system with strong reflection present
RCB - R CrB type eruptive variable
RR - RR Lyr type pulsating variable
   RRAB - asymmetric light curve
   RRC - nearly symmetric, sometimes sinusoidal, light curve
RS - RS CVn type eruptive variable
RV - RV Tau type pulsating variable
   RVA - does not vary in mean magnitude
   RVB - varies in mean magnitude with periodicity
S - unstudied variable with rapid light changes
SD - close binary eclipsing binary, semidetached system
SDOR - S Dor type eruptive variable
SEYFERT - Seyfert galaxay
SN - supernova eruptive variable
SR - semiregular pulsating variable
   SRA - giant with persistent periodicity
   SRB - giant with poorly expressed periodicity
   SRC - supergiant
   SRD - giant or supergiant with emission lines in spectrum
SXARI - SX Ari type rotating variable
SXPHE - SX Phe type pulsating variable
UG - U Gem type eruptive variable (dwarf nova)
   UGSS - SS Cyg subtype
   UGSU - SU UMa subtype
   UGZ - Z Cam subtype
UV - UV Cet type eruptive variable; flare star
WD - close binary eclipsing system with white dwarf components
WR - close binary eclipsing system with Wolf-Rayet star component
X - x-ray source, close binary system with one component a hot, compact object
  XBP - x-ray burster, showing optical and x-ray bursts
  XI - x-ray irregular
  XJ - x-ray binary with relativistic jets evident in x-ray and radio
  XM - x-ray magnetic variable (AM Her type = polar) with no pulsar or
       reflection effect
  XN - x-ray novalike system
  XND - x-ray novalike system containing a dwarf or subgiant
  XNGP - x-ray novalike system containing a giant or supergiant and a pulsar
  XP - x-ray pulsar system
     XPM - x-ray magnetic variable (AM Her type = polar) with pulsar but no
           reflection effect
     XPNG - the same as XNGP
     XPR - x-ray pulsar system featuring presence of reflection effect
ZAND - Z And (symbiotic) eruptive variable
     ZANDE - with eclipses
ZZ - ZZ Cet type pulsating variable
