In Alpha Chi Rho, the letter Upsilon is taboo and is never used:
A chapter, Phi Upsilon, was founded at the University of Iowa in 1899; but the members, being at a great distance from the other chapters and dissatisfied with the youth of the fraternity, developed disloyalty in 1901, and the fraternity in 1902 expelled the entire chapter and the remaining members joined the local chapter of Kappa Sigma.
From that day on, no chapter would use the letter. That's our take on the letter Upsilon. So we probably pronounce the letter as OOPS-silon considering our situation
AXPAlum