looking for mqh doc

 

as a noob i'm searching an as complete as possible doc/book/thread/.... about mqh and the relationship with mq5.

Interested by:

- why mqh are needed and how to create them

- how works all these embedded mqh together and each others

- how to call their internal declarations into mq5

- what is not possible with them

- what happen when we share an mqh with several EA/indicators  on same pair or multi pairs (conflicts, are arrays secured by tf/pair/indi/EA ?)

- ...

thanks for pointing some usefull topic/url if you knows ones.