Polarity Indicators on Current Source Symbol

[eev_carl]

Hi,

Is it common to list a polarity on current sources as in this photo from my workbook?  I searched through a few hundred images and didn't see any other examples of this online.

Thanks,
Carl

[Ian.M]

IMHO No.  The symbol should of course have an arrow to indicate the direction of positive conventional current flow, but as the polarity of the voltage across its terminals will depend on the circuit it is connected to, adding + and - there as part of the symbol is just misleading.