Editorial.

In all following sections, the word grouping should be replaced with merge (key).

- Current 4th para under 15.6.2 fn:current-merge-key:
"While an xsl:merge instruction is being evaluated, the current grouping key will be[...]"

- Current 6th (last) para under 15.6.2 fn:current-merge-key, first sentence:
"The grouping keys of all items in a group are not [...]"

- Same, last sentence:
"[...]The current-grouping-key function returns the grouping key of the initial item in the group,[...]"

- Under 15.6.2 error definitions:
"[ERR XTDE3510] It is a dynamic error if the current-merge-key function is used when the current grouping key is absent[...]"

In the following, replace current group with current merge group.

- Current 5th para under 15.6.1, fn:current-merge-group:
"Duplicates are not eliminated: for example, if the same node is selected in more than one input sequence, it may appear twice in the current group."

Other notes:
(potentially not just editorial)

- Under 15.6.2. a sentence like the following, which is present for fn:current-merge-group, is not present for fn:current-merge-key. This seems either an inconsistency, or simply an omission:

"All invocation constructs set the value of the current merge group to absent."