Mark Opportunity Fields as Read Only for a Record Type
Step 1. Open App Launcher.
Step 2. Enter text customize opp layout in the search bar and click Customize Opp Layout in search results.
Step 3. Select a Record Type such as RFP and click Go.
Step 4. RFP Page Layout opens, go to any field in this layout and click the wrench icon.
Step 5. Select the Read Only checkbox and click Update.
Similarly, you can mark other fields as Read Only.
Step 6. Click Save.
Step 7. Go to Opportunities using App Launcher and click to open an Opportunity record of the RFP Record Type.
Opportunity record page opens, note that the highlighted fields below are NOT editable as they were marked as Read Only in previous steps.
IMPORTANT
When you mark a field as Read Only:
Field(s) become Read Only exclusively on the Page Layout of the selected Record Type and NOT in other Record Types.
Field(s) become Read Only for all users including System Administrators.
NOTE
You can also use this feature to mark ALL fields as Read Only for a custom Record Type that an Opportunity can later be converted into, once it is Closed - making its complete information NON-editable to all its users.