The snap appeals to the visual and auditory senses.
It is also commonly used in SMS texting or via instant messengers.
OML is a replacement of OMG or OMFG which is mostly used to make oneself stand out.
What is the full form of XOXO? FYI: For your information 23.
SFW: Safe for work 57.
It is a slang word so you should not use it during the professional or business communication with others.