Glide = big A whereas No glide = Little A?

Hi Guys.
I was logging a recently installed Carrier Chiller today.
Which Has the refrigerant details listed (On Data Plate) as R410a.

However on my most recent comparator the R410 is listed with a Capital A!

All the other refrigerants with a Capital A have the Bubble and Dew options

The R410 option does not.

Is this because the difference between the bubble and dew point is so small?

Or is there another reason why it has a capital A.


I know this was answered a long time ago, but I have forgotten the answer.
Thanks Grizzly

Zeotropic mixtures shall be assigned an identifying number in the 400 series. This number designates which
components are in the mixture but not the amount of each. To differentiate among zeotropes having the same
components with different amounts (percent by mass), an uppercase letter shall be added as a suffix.
The numbers are in chronological order of the refrigerant’s approval by ASHRAE.
Example: R407A (R32/R125/R134a (20/40/40)), R407B (R32/R125/R134a (10/70/20)), R407C
(R32/R125/R134a (23/25/52)), R407D (R32/R125/R134a (15/15/70)), R407E (R32/R125/R134a (25/15/60))

Taken from the International Institute of Refrigeration.