New construction/renovation up here has a 20 amp dedicated sign circuit at the storefront facade/soffit/canopy etc. This has been since at least the 60's/70's. Also, IF the space had a tenant with signage that exceeded 16 amps, an additional circuit would be installed.
Show window receptacles/circuitry dedicated as required based on storefront. (But NEVER enough for liquor stores)
I agree with Reno; 600.5(A) has nothing to do with any signage except the storefront, be it soffit/facade/canopy.
Reno:
Yes, modifications for tenant changes causes a lot of havoc with existing circuitry, and the temptation of 'snagging' the sign feed, or the show window feed for something 'new' is common....but most if not all of us inspectors catch it.
