Forming the plural of a word ending in O can be tricky. Do you add ES or just an S? It depends on the word, and according to the American Heritage Dictionary, for some words (like placebo and pinto) either spelling is acceptable.
What’s a writer to do? Consulting a dictionary is just too time-consuming. Oh, the heck with it! Let’s just add an apostrophe and an S and be done with it!
That’s what Yahoo! Travel Help did. In the face of the other annoyances in this snippet (like the missing apostrophe in Users and the creatively capped Submit), an unnecessary punctuation mark seems like a minor slip.
