Standardization of emoji usage

Not being a big user of social media, I was nevertheless fascinated by the uptake of emoji and its various forms (same with emoticons when it first caught on). I am wondering whether there has been any standardization on the use of emoji in general IM and online conversation in the same way emoticons were (although there were a lot less variations and styles possible).

By standardization I am referring specifically to three different areas:

• The type of applications (both within and outside of IM) where it is acceptable and common to use emojis
• The meaning of frequently used emojis (across different languages or cultures)
• The way emoji messages are constructed, i.e. the 'grammar' or 'syntax' (I get very confused when there is more than one used)

One example of how emojis can be standardized can be seen on the emoji search engine website (http://www.emojiengine.com/). They have applied a combination of visual (by the layout of all the emojis by shape, size, etc), language/culture (you can select the language, which will change the context of the emoji) and also keyword/tag (the primary way to search I believe).

It would be interesting to see if there are other ways to go about this.