When choosing a motor does the acronym RGZESD have a specific meaning or does it just stand for High Eff TEFC?

When choosing a motor does the acronym RGZESD have a specific meaning or does it just stand for High Eff TEFC?

It looks like this is a Siemans Model designation. The RGZE may have some internal Siemans meaning, but it is not obvious from their website.

SD does mean Severe Duty.

See their website [1]

Niel