Frontend always includes sign of the constant, server always drops it. Frontend treats supported suffixes correctly, server doesn't.

Trigger expression:

1+0*({references:dummy.last()}=-1.23G + {$NUMBER})

Trigger name:

reference test one '$1' two '$2' three '$3' four '$4' five '$5'

Macros:

{$NUMBER} => -456.78w

What I see in Monitoring->Triggers/Problems:

reference test one '1' two '+0' three '-1.23G' four '-456.78w' five ''

What I see in notifications:

reference test one '1' two '0' three '1.23G' four '456.78' five ''

P.S. Discovered in trunk, affected versions filled up based on svn ann and revision numbers.