XTCE12 — Xpath:

– Xpath: xpath is the XML answer to unix-style paths but includes MATCHING, the ability really to get some chunk of any XML document using an Xpath expression. We should consider Xpath as the format for Refs... but there needs to be a technical debate.

"... A reference to a Parameter. Uses Unix ‘like’ naming across the
> SpaceSystem Tree (e.g., SimpleSat/Bus/EPDS/BatteryOne/Voltage). To
> reference an individual member of an array use the zero based bracket
> notation commonly used in languages like C, C++, and Java."

No Xpath for cross-references

Requiring an Xpath definition for the cross-references would break existing XTCE exchange implementations and would not necessarily reduce the amount of code required to implement an export or import tool.