Use of 3 mm square screw-driver?

[Rico-2]

What are the possible applications of a 3 mm wide Robertson screw-driver? I mean a 3 mm male square screw-driver in a multi-tool.

Could that be, to attach a bit-driver, for example? Three mm is 0.12 inch.

[Walley]

sounds like a No.2 Robertson, they are around 3mm I think? it's a very common screw in Canada.
 if I could only have 2 screwdriver bits on me it would be No.2 Phillips and No.2 Robertson.