Comet appellation
for example Hale Bopp C/199901

C/ 1999 0   1
First letter Discovery year Half month letter   follow up number
         
C = Comet

A = Astro´de / Planeto´de

X = Non confirmation

D = Disappeared / broken up

January A  
B  
February C  
D  
March E  

17/PHolmes

If it appears that the comet is short periodical, and has a fixed course with an orbit period of less than 200 years, it is recorded in the Short Periodic Comet Catalogue. This catalogue lists 194 comets and is in order of discovery/confirmation. The list starts with 1P/Halley (P/ stands for periodic), 2P/Encke, 3D/Biela (since broken up), 4/P Faye, etc. Komet 17/PHolmes is therfore the 17th Short Period comet on the list (discovered in 1892).
 

See also: http://www.aerith.net/index.html

F  
April G  
H  
May J  
K  
June L  
M  
July N  
O  
August P  
Q  
  September R  
  S  
October T  
U  
November V  
W  
December X  
Y