Under Construction...
The resources for a program can include a string table. A string table associates an ID number with a string. This can be useful for specifying error or status messages.
In fact, it is a good idea to separate the output messages of a program from the code which does the output, and especially from the code that generates the event which eventually leads to output. A string table makes it easier to modify the output of the program, to standardize error messages for example, without digging through the source code looking for strings. However, many programmers still include literal strings distributed throughout their source (like me, for example).