Linux in a Nutshell, 6th Edition

Addresses

If no address is given, the current line is the object of the command. If the address specifies a range of lines, the format is:

x,y

where x and y are the first and last addressed lines (x must precede y in the buffer). x and y may each be a line number or a symbol. Using ; instead of , sets the current line to x before interpreting y. The notation 1,$ addresses all lines in the file, as does %.