The phrase "hat tip" is a way of showing gratitude or acknowledging someone's help or contribution. It is similar to saying "thanks" or giving recognition to someone for their assistance or insight. Full definition
The wall text, bending over further than usual to make Alÿs look serious, will tell you it's a work about «the present chaotic state of Mexico» [Hat tip Roberta Smith for the quote]. (artfcity.com)
From the other side, one guy's perspective on two years of online dating (with hat tip to Harper's Index). (thehungoverwidow.com)
Big hat tip goes out to WU FB members Angie Ledbetter, Mara Buck, Cat Robinson, Beverly Diehl, Tonia Marie Harris, Layla R Cox, Jackie Phillips, David B. Schlosser, Andrea van der Wilt, Kristin Pedroja, Susan Girolami Kramer, and a few writers who wished to remain anonymous as well. (writerunboxed.com)