SWAN subroutines at top level can be given any name, because the user is familiar with these routines.
The names therefore need to be mnemonic. It is recommended to opt for specific combinations for
underlying subroutines, however, so that users with their own programming do not run into name
conflicts. The suggestion is to start all SWAN routines with the letter combination sw.
Unambiguous names are also necessary for the modules. For SWAN, the combination swmod could for example
be followed by a 3-digit symbol.
In any case, it is essential that an ASCII file with applied subroutine
names and modules is kept up-to-date, including a brief description of the functionalities.