Routing Logic Directives (RLD) built into EPISHIP control shipments through the rate and label manifest processes of the supply chain.
The purpose of this article is to detail the Afferent Reference Rule, a specific RLD Rule type, that targets the transformation and control of reference field information before a rate or label request is processed.
A rate or label request utilizes reference fields to pass critical information—such as Purchase Order (PO) numbers, invoice numbers, internal billing codes, or custom customer messages—so that they are printed directly on the shipping label or returned in the carrier’s billing files. Sometimes, the default reference data submitted from an upstream system (like an ERP or WMS) is missing, improperly formatted, or placed in the wrong field for a specific carrier’s requirements. This is where the Afferent Reference Rule comes in. Unlike Efferent rules that post-process carrier responses, the Afferent Reference Rule pre-processes the request to explicitly modify the reference details (e.g., dynamically injecting a department code, truncating a long PO number, or mapping data between reference fields) before the request is ever submitted to the carrier network. The Afferent Reference Rule is one rule type within an RLD Template.
Any number of Afferent Reference Rules can be built within an RLD Template to match business objectives. Each Afferent Reference Rule includes the following components.
Match conditions of criteria operators include the following types: All (AND), Any (OR), None (Not).
Sender fields available for match criteria include the follow properties:
Receiver fields available for match criteria include the follow properties:
Package fields available for match criteria include the follow properties:
Line Items fields available for match criteria include the follow properties:
Options fields available for match criteria include the follow properties:
References fields available for match criteria include the follow properties:
Rate fields available for match criteria include the follow properties:
Time fields available for match criteria include the follow properties:
The match criteria types listed above are used within individual rules or can be combined into a single rule to target specific conditions that include several match criteria.
The shipment request is modified according to the rules defined within the Afferent Reference Rule matched within the RLD Template. The transformation functionality available to be included within the RLD template is as follows.
This configuration dictates exactly how the reference properties are altered in the outgoing request payload. Once the match criteria are met, the request is transformed to override, inject, or clear specific reference fields—such as Reference 1, Reference 2, or Reference 3—with explicitly defined replacement values before the carrier generates the label.
Usual use cases for Afferent Reference Rules within an RLD Template are numerous. Some common use cases include the following:
Automatically inject a specific internal department billing code into Reference 2 whenever a particular sender origin is used, ensuring accurate carrier invoice reconciliation.
Map a specific Line Item SKU or the Receiver Company Name into Reference 1 so that it visibly prints on the shipping label to aid warehouse receiving for B2B customers.
Append a standardized message (e.g., “Do Not Leave on Porch” or “Happy Holidays!”) to Reference 3 during specific times of the year or when high-value items are detected in the cart.
