Fanon talk:Olive Specter (STM)/@comment-24258073-20140218084712/@comment-4568327-20140407141552

When Sims die, their character files remain intact. The gravestone is basically the dead Sim. When you delete the tombstone, the effects are the same as deleting Sims in the family bin, which will corrupt your neighborhood. The character files are still there, but the game has damaged them. They cannot be resurrected.

If you have Pescado's No Unlinkage on Delete mod, the character file of a Sim who's tombstone has been deleted will not be shredded or damaged, and you can technically resurrect such Sims. The mod only fixes instances of Sims that were deleted after the mod was installed.

Since the game has difficulty letting graves, well, rest in peace, the mod is essential to preventing corruption caused by the game deciding to disturb the graves of Sims.