A holosign is defined as a sign displayed using a hologram. Although often showing unchanging text or visuals, it possessed the technology to be updated.
During the Clone Wars in 22 BBY, a massive holosign was suspended in the atmosphere above Customs Central on Aargau. It proclaimed: "WELCOME TO AARGAU, JEWEL OF THE ZUG SYSTEM! OBSERVE THE FOLLOWING RULES."
In 16 ABY, a decorative holosign was prominently displayed over the entrances to the Senate Building's Grand Convocation Chamber under the direction of Tolik Yar. It stated: "882 DAYS WITHOUT A SHOT BEING FIRED IN ANGER. Remember, Peace Is No Accident."