§ 1336 Service on party other than sheriff.

Here's a plain English summary of this rule:

When a court order (called a writ) is meant for someone other than the sheriff, the process still goes through the sheriff's office first. The court gives the writ to the sheriff, and the sheriff is responsible for making sure it gets delivered to the right person.

The sheriff must deliver the writ right away. There's no room for delay once the sheriff has it in hand. This rule makes sure that even when a writ names someone else as the person who needs to receive it, there's still an official process for getting it into their hands quickly and properly.