Re: Charles E. Voigtsberger’s March 28 letter, “No way to flip a thank you":

I believe there are several universally recognizable hand-signals to do just that. One is an open-handed, palm facing inward touch to the forehead and then extending outward towards the recipient.

Others may be discovered by becoming familiar with those who are conversant in American Sign Language for the hearing-impaired. Many of those signs are also universally recognizable.

— Mark Voland, Ventura