What does the 'W' written on my passport by Thai immigration mean and will it affect my return for Christmas?

A user recently inquired about a notation 'W' written on their passport by Thai immigration upon exiting Phuket Airport and whether it would cause issues for future visits. Various comments suggest that the mark could have several interpretations, including it being a simple signature from the officer, a notation for visa exemption entry, or even a playful reference indicating a free beer on their return. Several participants offered humor and reassurances that there is typically nothing to worry about regarding such marks.