COVID AND THE VACCINE - TRUTH, LIES, AND MISCONCEPTIONS REVEALED, page-86348

True mandates are a request, which is why they are often paired with a default action that will be taken if you don't comply.

For example, and simplified, we mandate that you wear a mask on public transport, failure to comply will result in you being barred from ysing public transport.

So the mandate is optional because we're not forcing you to use public transport so we can't force you to wear a mask, but a condition of using public transport is that you wear a mask.