The Windows 95 LPT enumerator (LPTENUM.VXD) does not call VCOMM to detect LPT devices; instead, it writes directly to the port. When called to enumerate devices attached to an LPT port, the enumerator calls ACQUIRE_RESOURCE with ACQUIRE_NO_STEAL, so that it does not inadvertently interfere with another program using the port.
Unlike the COM enumerator, LPTENUM calls RELEASE_RESOURCE when it is done checking a port, because it cannot detect a device attach or device detach operation.