China Mobile China Mobile Centec Centec Centec Inesa SAIA In Situ Operations, Administration, and Maintenance (IOAM) enables on-path telemetry by inserting operational metadata into data packets as they traverse a network path. IOAM Data-Fields, as defined in RFC 9197, are designed to be independent of the encapsulating transport protocol. However, the procedures for inserting, updating, and removing IOAM Data-Fields are currently specified separately for each transport protocol (e.g., IPv6, NSH, GRE, Geneve), leading to redundant specification effort and inconsistent implementation behavior. This document defines a set of common encapsulation procedures for IOAM Data-Fields that are applicable across multiple transport protocols. The insertion point for IOAM Data-Fields is expressed as a configurable byte offset from a well-defined reference position in the encapsulating header, enabling a uniform insertion procedure that does not require protocol-specific parsing logic. The document specifies the general steps for identifying the insertion point, validating transport-layer constraints, performing the insertion of IOAM Option-Types, and updating affected header fields to maintain protocol compliance.