I went into PSA in Plano yesterday and they had a "vote yes for the PISD bond package" sign out front.  I thought election signs on public property were prohibited.  

Is this type of sign permitted on public park property?

Have you ever voted?
Visit Carpenter Park Rec Center during early voting or on election day and you'll see dozens of signs.

Yes but there are minimum distances required from polling places.  I just couldn't find anything about election signs on public property outside of voting times.  

ETA: Found it - Plano municipal code, unless it's a polling place the sign probably needs to come down.  

Sec. 6-491. - Political signs/noncommercial purpose signs.

(1)

Political and noncommercial purpose signs thirty-six (36) square feet or less are allowed on private property with the consent of the property owner.

(2)

Political and noncommercial signs are prohibited on public property except as follows:

(a)

Political signs four (4) square feet or less may be placed on the premises of city owned or controlled buildings being used as active polling places except where otherwise prohibited by state law or this section. Political signs erected pursuant to this subsection may be displayed at active polling places no earlier than one (1) day prior to the first day of voting at each polling place and must be removed within three (3) days following the last day of voting at each polling place for each primary, general and special election.

(b)

Political and noncommercial purpose signs are prohibited in the rights-of-way at all times.

(c)

City personnel may remove and dispose of any sign placed on public property or within the rights-of-way in violation of this section.

It's not "public park property". PSA owns the building, not City of Plano.
Same at PSA locations in Murphy & McKinney.

Just checked collin county cad, that's a recent change.  That property used to be listed as owned by the city of plano.....very interesting.