Column / Row Level Security
Example: One list has a column with Security Clearance. Security Clearance has three options, Classified, Secret, Top Secret.
Users that have Classified can only see items which are designed Classified, User with Secret can see Classified and Secret items while Top Secret can see all three. Has many more uses other than this simple example.
Star D. commented
We've created documents where one audience needs to fill out the top portion, but the bottom is for another group (e.g. security, HR, etc). While we can hide those columns in a view, that won't keep users from accidentally changing those fields in the details/properties.
This is often even more problematic because often those field values trigger workflows.
If we had the ability to control column access via permissions, we wouldn't have to worry about people "staying in their lane".
Oleg Bulatovsky commented
ArtfulBits Column Permissions supports setting read-only and hidden permissions for individual columns and users. You can try it out and find more info following the link below:
The row security that exists is the 'Item-level Permissions' in the advanced settings, it is possible to allow only the user who created the item to read or edit it. But if the item must be transfered to another user, it's not possible to change de Created by field. Also this cannot be used on files in libraries.
Kushal Arora commented
Row level security is already there. But yes, we need column level/view level security