When should we pro-rate Annual Leave?

I would like to check on when should we pro-rate Annual Leave? I've only known of pro-rating of AL its only being done when if an employee served the employer for at least 3 mths or they work for less than a year or when want to resign & also with regards to Encashment of Annual Leave, it is compulsory for us to encash the Annual Leave for those employee who wants to take cash instead of leave and what is the maximum days to encash annual leave and also do we need to pro-rate annual leave if they want to encash their leave?

If an employee has worked for less than one whole year, i.e. less than 12 months, his annual leave should be pro-rated.

Active employees who have not taken their annual leave for the year, Company’s leave policy shall determine whether to (i)encash leave, (ii)carried forward leave, or (iii)forfeiture of leave

For resignation, any unconsumed annual leave can be encashed by the employee.
For termination of an employee's service not based on misconduct, the employer must pay him for every day of unconsumed leave.