Any small personal gadget such as a phone, tablet, smartwatch or e-reader that can hold or share data.
Like the things a visitor carries into a building that security may want to check.
A staff member's tablet with client files was left on a train. With no passcode, the files could be opened by anyone who found it.
What is the simplest rule?
Require a passcode and the ability to wipe a lost device before it holds any work data.
Every WILDCARD card exists to solve one named problem. Find yours.