An assembler program can be plain or compound one. A plain assembler program is the content of a single assembler procedure. A compound assembler program consists of multiple procedures possibly intended for loading into distinct model nodes.
By default, the assembler program parser reads comments contained in an assembler program and saves them in its memory representation. For the identification of comments to be correct, their arrangement must adhere to certain rules.
When expanding macros or including other files in an assembler source file, the assembler preprocessor inserts line directives in preprocessed output for handing over source file, macro, and line number information to the assembler program parser for inclusion in its error, warning, and note messages and for inclusion in error, warning, and note messages of node assembler.