what is optimization update ?

https://help.forumotion.com/updates-and-new-features-f1/optimization-update-few-cool-features-t43613.htm


please check the link above...do we have to do changes in our template ?

if so then please help me how to do it...


This update says that we can add as many users as we want while sending a pm...but in my pm box i cannot see the + icon to add more users...

Only if you have a customized template you will need to do changes. The changes that need to be done are mentioned in the thread itself.

do cutomized template means that if i've done some changes in the default template, is that is called a customized template ?

Yes, that is correct

how to do it ??????? ....i dont know...

You only need to do anything if u have edited your forums template (and that's on PHPBB2 only)