2.1.7 [CSS-Level2-2009] Section 4.3.1, Integers and real numbers


The specification states:

 Some value types may have integer values (denoted by <integer>) or real number 
 values (denoted by <number>). Real numbers and integers are specified in decimal 
 notation only. An <integer> consists of one or more digits "0" to "9". A <number> 
 can either be an <integer>, or it can be zero or more digits followed by a dot (.) 
 followed by one or more digits. Both integers and real numbers may be preceded by a 
 "-" or "+" to indicate the sign. -0 is equivalent to 0 and is not a negative 

Quirks Mode (All Versions)

A <number> that has no digits following the dot (.) is allowed. For example, "10.em" is correctly parsed.