The Java EE 6 Tutorial, Volume I

BNF Symbols

Table 21–1 describes the BNF symbols used in this chapter.

Table 21–1 BNF Symbol Summary




The element to the left of the symbol is defined by the constructs on the right. 


The preceding construct may occur zero or more times. 


The constructs within the curly braces are grouped together. 


The constructs within the square brackets are optional. 


An exclusive OR.


A keyword (although capitalized in the BNF diagram, keywords are not case-sensitive). 

White space 

A white space character can be a space, a horizontal tab, or a line feed.