If you are working with multiple currencies you might want reserve some accounts to only use specific currencies and avoid posting happening to accounts. There is an options when you setup can account to validate the currency being posted through to the account.
There is a quick look at the setup and effect of the currency validation on a GL account.
Cheers
Lachlan
OrganicAX 
Pingback: GL accounts setup for currency validation – sales invoice posting example | OrganicAX·
Pingback: GL accounts setup for currency validation – sales invoice posting example - Microsoft Dynamics AX Community·