It is listed as a miscellaneous item, as it cannot be equipped by the Sole Survivor (who would already wear a Pip-Boy of their own), but it can be equipped by some NPCs, such as Clem. Most settlers and humanoid companions, apart from Hancock and Nick Valentine, will also equip it if given to them.
Instead of having to tell a settler to equip, it will automatically be equipped as soon as it's on their inventory. And when that happens, it disappears from their inventory, making it impossible to get it back even if the settler dies.
PCPlaystation 4Xbox One When the Pip-Boy is placed in the settler's inventory, it will not automatically equip, remaining as an item in their inventory indefinitely.[verified]
To work around this, get all (new) Pip-Boys from the Pip-Boy crates and Vault steamer trunk in the entrance area. Transfer all Pip-Boys to the settler one at a time. Usually, three Pip-Boys will be taken from the stack, the settler will equip one, and you can take the remaining ones back to give them to other settlers. NOTE: If you give them more than one functional one, I.E. your whole stack, they can equip more than one, and you might be left with nothing but the broken ones in their inventory, similar to the companions below.
Open the console and select the NPC or companion you want to equip with a pip-boy. Type ShowInventory to verify you have the correct NPC. Then type EquipItem xx0042af (XX representing the load order of Vault-88 DLC).
If a Pip-Boy is given to a companion capable of equipping items e.g. Piper, Cait, Preston, etc. but the companion does not immediately equip the Pip-Boy given, fully dismiss the companion first to any settlement when the menu is displayed and immediately recruit the companion again. The Pip-Boy can then be given and will be immediately equipped by the companion.
Warning: Only 1 Pip-Boy should be given the companion. If more than 1 (or all) of the Pip-Boys are placed in the companion's inventory (as per the settler workaround above), the numbers will rapidly decrease until only 1 Pip-Boy is left which is then equipped by the companion. The other Pip-Boys are irrevocably lost and can only be replaced by console commands.
PCPlaystation 4 Some settlers who are given Pip-Boys will unequip them at a later point.[verified]
Xbox One Sometimes, the Pip-Boy will cause a crash when viewed in the inventory, making them impossible to drop or give to NPCs.[verified]