CATIA FT&A How to apply MBC to a datum in the semantic reference frame.

[supergee]

Hi everyone

I am studying to pass my GD&T certification and I felt like taking a break by trying to create some of the example in CATIA (how to make a dry subject juicy right!!!) but I am not able to add the MBC on the datum while creating a semantic dimension.

If your confused about MBC, it is the M inside a circle symbol, just like MMC, but it changes name when applied to a datum instead of a tolerance.

I can create it with a non semantic dimension but I heard it's a big no no (though I don't know why... if you could explain as a bonus I'd appreciate )

basically I want to have something like this |A|B(m)|C(m)|

thanks!!!