http://www.statutes.legis.state.tx.us/D ... /PE.30.htm
Emphasis mine.Sec. 30.06. TRESPASS BY LICENSE HOLDER WITH A CONCEALED HANDGUN. (a) A license holder commits an offense if the license holder:
(1) carries a concealed handgun under the authority of Subchapter H, Chapter 411, Government Code, on property of another without effective consent; and
(2) received notice that entry on the property by a license holder with a concealed handgun was forbidden.
(b) For purposes of this section, a person receives notice if the owner of the property or someone with apparent authority to act for the owner provides notice to the person by oral or written communication.
(c) In this section:
(1) "Entry" has the meaning assigned by Section 30.05(b).
(2) "License holder" has the meaning assigned by Section 46.035(f).
(3) "Written communication" means:
(A) a card or other document on which is written language identical to the following: "Pursuant to Section 30.06, Penal Code (trespass by license holder with a concealed handgun), a person licensed under Subchapter H, Chapter 411, Government Code (handgun licensing law), may not enter this property with a concealed handgun"; or
(B) a sign posted on the property that:
(i) includes the language described by Paragraph (A) in both English and Spanish;
(ii) appears in contrasting colors with block letters at least one inch in height; and
(iii) is displayed in a conspicuous manner clearly visible to the public.
(d) An offense under this section is a Class C misdemeanor punishable by a fine not to exceed $200, except that the offense is a Class A misdemeanor if it is shown on the trial of the offense that, after entering the property, the license holder was personally given the notice by oral communication described by Subsection (b) and subsequently failed to depart.
Gun buster sign by itself, or any other rendition of a sign that is no guns permitted, carries no weight of law. A card with the 30.06/30.07 verbiage handed to you does. Any verbal communication that you can't carry does. Of course, a 30.06/30.07 sign properly posted does as well.