4.3. Descriptors and Signatures
A descriptor is a string representing the type of a field or method. Descriptors are represented in the
class file format using modified UTF-8 strings (§4.4.7) and thus may be drawn, where not further constrained, from the entire Unicode codespace.
A signature is a string representing the generic type of a field or method, or generic type information for a class declaration.
4.3.1. Grammar Notation
Descriptors and signatures are specified using a grammar. This grammar is a set of productions that describe how sequences of characters can form syntactically correct descriptors of various types. Terminal symbols of the grammar are shown in
bold fixed-width font. Nonterminal symbols are shown in italic type. The definition ...