txinvestigator
TGT Addict
Section 411.204 of the Texas Govt. Code states it is to be prominately displayed at each entrance to the business.
subsection (c) requires the sign to in both English and spanish, apppear in contrasting colors with block letters at least one inch in height, and as you've already noted it must contain the number "51" in solid red at least 5 inches in height, and be in a conspicuous place visible to the public.
Section (e) is catchy, it states this section(411.204) does not appy to an establishment that has a food and beverage certificate issued under the Alcohol Beverage Code.
Ya know they do that on purpose, because if it 411.204 doesn't apply they get'em with Chap 11 or 61 of the Alcohol beverage code, requiring the business to post the other sign.
Best thing to do is keep your eyes open, your lips shut and your partner concealed.
Just remember, none of that has any effect on the penal code making it a crime to carry in a 51% location. It means nothing to CHL holders.