WARNING! This tutorial is extremely simple and easy. Please do not call me a newb/noob.
On with the tutorial! What this does is make items un-equipable if a player does not have sufficient rights to do so. You can make it effected by playerRights, username, status, etc. Have fun with it! 
Note: The example I'm giving you looks a bit unclean, but it condenses it in the long run 
Step 1: Search for "public boolean process()" in your client.java.
Step 2: Add this somewhere under it (you can add multiple instances of this one code):
Code:
/* Reserved/Disabled Armor/Weapons/Etc. */
if(playerEquipment[playerWeapon] == ITEM ID && NEEDED TO USE)
{ remove(playerEquipment[TYPE], TYPE); sendMessage("MESSAGE"); }
Replace the following with...
- ITEM ID: The item ID you wish to reserve/disable.
- NEEDED TO USE: This is the condition that player can/cannot have to use.
- TYPE: All of these needed to be replaced with the equipment type, such as "playerWeapon" or "playerShield."
- MESSAGE: What message you want to send after un-equipping the item.
That should do it! If you like and/or used this code, please give me some Rep+ and don't leech. Also, post here with comments or if you need help with this code. Thanks