The Welcome Back Sign is an Easter egg in Grand Theft Auto V.
Description[]
It is located in Chamberlain Hills, Los Santos, near the Clinton residence. The large graffiti sign says "WELCOME BACK" in the large green font. Below it is a skull wearing a bandana and a hat bearing the Grove Street Families colors, and wielding two pistols. Below the skull is some more graffiti reading "We missed you last time", possibly referring to Grand Theft Auto: San Andreas.
On the two upper corners of the wall are the letters "SA 88". This is a reference to the birth date of Franklin Clinton, which was in 1988. In the game, the Chamberlain Gangster Family members can be frequently seen loitering around the sign. The graffiti is believed to be an Easter egg welcoming players back to San Andreas from GTA San Andreas. Some players have theorized that Franklin made it during his time with the gang.