In about 1941 Brunswick named a full splice one-piece cue the "Titlist". It distinctive classic colored veneers with light blue, rosewood, and purple. The name "Willie Hoppe" was burned into the forearm.
Over the next several decades, this became the most popular veneered cue in history. The famous cue makers of the era, including Rambow, Balabushka, Balner, and Paradise all made cues using this cue as the basis.
Just as the "Mauser" became the most popular and famous bolt action for a custom rifle, the term "Titlist conversion" means a cue built into a custom cue from Titlist forearm.