Custom Scale Text Display

Here in Korea, architects are mostly using metric system and prefer to write Scale text with fraction style.
If 1mm=100mm, then we make it displayed 1/100 at title.

Here is an example.

Text String Value in Formula

As it is known that string value can't be used for results of  formulas. It means...

At the family above, if the TYPE should be..

if A < B,  TYPE = X

if A > B,  TYPE = Y

if A = B,  TYPE = Z