When ALP processes an INCLUDE directive, ALP translates the value of the BaseEXE internal variable to uppercase and uses this value to construct the name of an ALP-specific environment variable having the form:
<BaseEXE>_INCLUDE
For example, If the value of BaseEXE is alp, then ALP constructs an environment variable called ALP_INCLUDE and tries to locate it in the environment. If found, its contents would be expected to contain a list of directories in a format identical to that of the standard INCLUDE environment variable.