I have custom object called candidate. I have created field name called first name which is read-only in the page layout. Once a record is created with first name field populated I am able to edit that field. Why I am able to edit (I mean getting pencil icon). Can anyone suggest me for this issue?
[SalesForce] Read only field not working in page layout
Related Solutions
Make Account name Field as Read Only in Case Page Layout
In a page layout on the field properties you can set the permission to read only.
However there may be fields that you cannot do this with, e.g Account name on the Account object and for those you would need to set the permissions using Field Level Security on the Profile.
Then using Record Type assignment of page layouts you can make the fields editable on one record type only.
Best Answer
Are you doing this as a system admin?
System Admin profile has the option "Edit Read Only Fields" under "Administrative Permissions" and this means that profile is always able to edit read only fields.
Try logging in as a user with a different profile.