I took a one million dollar coin and tried to enter "1 000 000" for the Face value in figure form but the modify button gave the error "Please match the requested format." for the field. I also tried:
Putting "1 000 000.00" in the field.
Instead of using my space bar I copied a non-breakable space from another web site.
Hello,
I made a change so that you can now use spaces in the field for the face value.
Note that this field is anyway formatted automatically, so spaces are optional for this field. The part of the guidelines you mentioned rather apply when you enter a number within some text field, like the title.