What is more understandable -> $EM_dash OR $event_manager_dashboard ?
Now you may think that making variables like $EM_dash is not problem, because anybody who is working on the code knows what it is for and it makes the code smaller.
As a result we have such names that are itself a code, r_id instead of role_id … and there are more.
But what happens when somebody else comes to work on the code?
It is very confusing. You would only know that when you get into reading a code written by somebody else; somebody who has different idea of written material than you have.
The reason people write short variable and column names is because they want to get things done faster. But the side-effect of this is that the code is more – well a code, not clear and people are prone to use same variable names more than once, which can result in malfunctioning software.
Although writing a longer name is tedious, but it has a lot of advantages. Hence try $number_of_items_bought rather than $ibought.