The ASN.1 BOOLEAN type has two possible values: TRUE and FALSE. You can define new types based on this built-in type.
ValueAvailable ::= BOOLEAN
The following examples show value assignments using BOOLEAN values. User-defined types can be used as well as built-in types. As shown below, the currentStatus and operationCompleted identifiers can be used anywhere a BOOLEAN value is required:
Married ::= BOOLEAN currentStatus Married ::= FALSE
operationCompleted BOOLEAN ::= TRUE
Present ::= BOOLEAN status Present ::= TRUE
In DER, the BOOLEAN type value defined in the example above is encoded as follows:
01 01 FF
The BOOLEAN type can be constrained by a single value or by type inclusion.