Italian Drawing Abbreviation Meaning

[DTC-NWI]

Hello,

Can someone who is familiar with Italian drawing standards clarify the meaning of "∅6 Cal." I'm not sure what the "Cal." abbreviation means. It is shown as a diameter dimension on a type of pin. Is it a type of slip fit tolerance? This pin is intended to slip fit in a different part. Any help on this is much appreciated.

Thanks,
DTC

 

[MintJulep]

I'd guess "calibro", which is an origin of the English "caliber".

In context probably "bore" (as a noun, not a verb), which seems redundant to the diameter symbol.

None of which offers any information regarding tolerances.