RFC 6241, "Network Configuration Protocol (NETCONF)", June 2011

Errata ID: 5401
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Rohit R Ranade
Date Reported: 2018-06-21
Held for Document Update by: Ignas Bagdonas
Date Held: 2019-10-18

Section 8.9.1 says:

   The XPath expression MUST return a node set.  If it does not return a
   node set, the operation fails with an "invalid-value" error.

It should say:

   The XPath expression MUST return a node set.  If it does not return a
   node set, the operation fails with an <error-tag> value of 
   "invalid-value".

Notes:

It is unclear what is the meaning of "invalid-value" "error". Since the xpath will be part of "select" attribute, we can assume that a server can return a "bad-attribute" error-tag and having error-message indicating invalid-value for the attribute. This clarifies the <error-tag> to be used in such cases.
In other places, where error-tag has been mentioned, it is clear that "invalid-value" <error-tag> must be used.

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