Peace Be Upon Him is generally used for the Prophets (Peace Be Upon Them).

For other people who are highly repected:

'Radi'Allahu Anhu' is used, which means 'Allah's blessings be on him'

OR

'Radi'Allahu Anha' is used for females, which means 'Allah's blessings be on her'.

The'ha' signifies the female gender in the Arabic language.

For instance:

• "Abu Bakr (Prophet Muhammad PBUH's Father-in-Law) Radi'Allahu Anhu"

• "Aisha (Prophet Muhammad PBUH's wife) Radi'Allahu Anha"

Peace Be Upon Him is generally used for the Prophets (Peace Be Upon Them).

For other people who are highly repected:

'Radi'Allahu Anhu' is used, which means 'Allah's blessings be on him'

OR

'Radi'Allahu Anha' is used for females, which means 'Allah's blessings be on her'.

OR

'Radi'Allahu Anhum' is used for male plural, which means 'Allah's blessings be on them'.

or

'Radi'Allahu Anhuma' is used for female plural, which also means 'Allah's blessings be on them'.

For instance:

• "Abu Bakr (Prophet Muhammad PBUH's Father-in-Law) Radi'Allahu Anhu"

• "Aisha (Prophet Muhammad PBUH's wife) Radi'Allahu Anha"