1. The environment variable is deleted if it is assigned an empty string.

2. Variables created or modified with this procedure can be retrieved using the getenv function and are inherited by processes started by system or openpipe.

3. The effect of this procedure is local to the running model ( i.e. system calls like the C function getenv will not work for these variables). However, another module may access the environment maintained by mmsystem using the IMCI function getenv (see Section Published library functions).

4. This procedure is included in the published interface of mmsystem (see Section Published library functions).