We have some rules concerning which classes and builds get “need” priority on certain items. You can find these rules on the following sub-pages. 

Some overall loot-rules:

Lootprio in following order: Oro Porfa Main (MS)/Pug (MS) over Oro Porfa Alt (MS) over Pug (OS)

For Molten Core. 

For Blackwing Lair

For Temple of Ahn’Qiraj (AQ40)

For Ruins of Ahn’Qiraj (AQ40)