Represents an identifier for compilation related tasks. An identifier constists of dash separated parts of character sequences of a-z, A-Z, 0-9, _, ., (), [], @. The identifier parts are normalized to lower-case representation. In general, identifiers are used for two things: 1. Determining the output location of the task. Different compilation tasks should have separate output locations in order to avoid overwriting each others data. 2. Merging common compiler options with the input configuration. Compiler options can bear an identifier that specifies to which input configurations should they be merged into. If all parts in the options identifier are present in the compiler task identifier, then the options may be merged into the input configuration. This behaviour may be different based on task implementations.