Places where the use of 小姐 is inappropriate
People say calling a woman 小姐 in Hong Kong and Taiwan is ok.  but not so good in Mainland China. I have to disagree with this presumption. It all depend on the context and the situation this term is used.

Generally 小姐 is a polite/ formal address for single woman in Chinese everywhere. 

For example: 

張小姐 (Miss Zhang)

我家小姐 (my daughter/ the daughter in the family I serve)

The term 小姐 can be interpreted as a nickname for prostitute because people in places where women provide various degrees of sexual service, would not use derogatory terms liked 舞女， 陪酒女郎 or even 妓女 to address the female sex workers directly, They just call them "小姐" (ladies) for politeness and subtlety. 

For example: "我們店的小姐" (the ladies in our establishment) ; "去做小姐" (go work as a Miss) would clearly imply 小姐 is not an honorific but a code for female sex workers in the context

Even in Hong Kong, people often refer 舞女 or 妓女 as 小姐 like in mainland China.

It is not ok. even in Hong Kong to ask a woman "妳係邊間店嘅小姐呀？" (which place's lady you are?)

One thing is sure. It is perfectly fine to address a female stranger as 小姐 in Hong Kong or Taiwan, No one would think 小姐 be anything but an honorific. 

Some people argued with me that 小姐 is ambiguous in Mainland and should be avoided. I thought those people just treated a specific nickname in a specific area as a general term 

小姐 is mainly an honorific/ title in Chinese , 张 in 张小姐 is that person's identify and 小姐 is an honorific/ title . But the term 小姐 itself can also be used as a code for female sex workers in certain context. And Mainland Chinese seem to be more sensitive to this additional usage than Chinese in Hong Kong and Taiwan