Add missing Cypher 25 updates (GQL extended identifiers + subqeury expression change)

modules/ROOT/pages/appendix/gql-conformance/index.adoc

@@ -1,7 +1,7 @@
 :description: Overview of Cypher's conformance to GQL.
 = GQL conformance
 
-*Last updated*: 2 June 2025 +
+*Last updated*: 18 June 2025 +
 *Neo4j version*: 2025.06
 
 GQL is the new link:https://www.iso.org/home.html[ISO] International Standard query language for graph databases.

modules/ROOT/pages/appendix/gql-conformance/supported-mandatory.adoc

@@ -211,10 +211,8 @@ In Cypher, `trim()` removes any whitespace character.
 | 21.1
 | Names and variables
 | xref:syntax/index.adoc[]
-| Cypher supports GQL’s lexical elements, with the following caveats:
+| Cypher supports GQL’s lexical elements, with the following caveat:
 
-* GQL allows for extended parameter identifiers.
-For example: `RETURN $0hello` is allowed in GQL but not Cypher.
 * GQL allows identifiers that are not variables to be delimited with both backticks and quotes.
 Cypher only allows backticks.
 For example: `MATCH (n) RETURN n."a prop"` is allowed in GQL but not Cypher.

modules/ROOT/pages/deprecations-additions-removals-compatibility.adoc

@@ -59,7 +59,7 @@ label:removed[]
 RETURN 1 as my\u0085identifier
 ----
 a|
-The Unicode character \`\u0085` has been removed for unescaped identifiers and is now considered a whitespace character.
+The Unicode character `\u0085` has been removed for unescaped identifiers and is now considered a whitespace character.
 To continue using it, escape the identifier by adding backticks around it.
 This applies to all unescaped identifiers in Cypher, such as label expressions, properties, variable names, or parameters.
 In the given example, the quoted identifier would be \`my�identifier`.
@@ -72,23 +72,23 @@ label:removed[]
 RETURN 1 as my$Identifier
 ----
 a|
-The character with the Unicode representation \`\u0024` has been removed for unescaped identifiers. To continue using it, escape the identifier by adding backticks around the identifier.
+The character with the Unicode representation `\u0024` has been removed for unescaped identifiers. To continue using it, escape the identifier by adding backticks (++``++) around the identifier.
 This applies to all unescaped identifiers in Cypher, such as label expressions, properties, variable names, or parameters. In the given example, the quoted identifier would be \`my$identifier`.
 
 The following Unicode Characters are removed in identifiers:
-'\u0000', '\u0001', '\u0002', '\u0003', '\u0004', '\u0005', '\u0006', '\u0007',
-'\u0008', '\u000E', '\u000F', '\u0010', '\u0011', '\u0012', '\u0013', '\u0014',
-'\u0015', '\u0016', '\u0017', '\u0018', '\u0019', '\u001A', '\u001B', '\u007F',
-'\u0080', '\u0081', '\u0082', '\u0083', '\u0084', '\u0086', '\u0087', '\u0088',
-'\u0089', '\u008A', '\u008B', '\u008C', '\u008D', '\u008E', '\u008F', '\u0090',
-'\u0091', '\u0092', '\u0093', '\u0094', '\u0095', '\u0096', '\u0097', '\u0098',
-'\u0099', '\u009A', '\u009B', '\u009C', '\u009D', '\u009E', '\u009F', '\u0024',
-'\u00A2', '\u00A3', '\u00A4', '\u00A5', '\u00AD', '\u0600', '\u0601', '\u0602',
-'\u0603', '\u0604', '\u0605', '\u061C', '\u06DD', '\u070F', '\u08E2', '\u180E',
-'\u200B', '\u200C', '\u200D', '\u200E', '\u200F', '\u202A', '\u202B', '\u202C',
-'\u202D', '\u202E', '\u2060', '\u2061', '\u2062', '\u2063', '\u2064', '\u2066',
-'\u2067', '\u2068', '\u2069', '\u206A', '\u206B', '\u206C', '\u206D', '\u206E',
-'\u206F', '\u2E2F', '\uFEFF', '\uFFF9', '\uFFFA', '\uFFFB'
+`\u0000`, `\u0001`, `\u0002`, `\u0003`, `\u0004`, `\u0005`, `\u0006`, `\u0007`,
+`\u0008`, `\u000E`, `\u000F`, `\u0010`, `\u0011`, `\u0012`, `\u0013`, `\u0014`,
+`\u0015`, `\u0016`, `\u0017`, `\u0018`, `\u0019`, `\u001A`, `\u001B`, `\u007F`,
+`\u0080`, `\u0081`, `\u0082`, `\u0083`, `\u0084`, `\u0086`, `\u0087`, `\u0088`,
+`\u0089`, `\u008A`, `\u008B`, `\u008C`, `\u008D`, `\u008E`, `\u008F`, `\u0090`,
+`\u0091`, `\u0092`, `\u0093`, `\u0094`, `\u0095`, `\u0096`, `\u0097`, `\u0098`,
+`\u0099`, `\u009A`, `\u009B`, `\u009C`, `\u009D`, `\u009E`, `\u009F`, `\u0024`,
+`\u00A2`, `\u00A3`, `\u00A4`, `\u00A5`, `\u00AD`, `\u0600`, `\u0601`, `\u0602`,
+`\u0603`, `\u0604`, `\u0605`, `\u061C`, `\u06DD`, `\u070F`, `\u08E2`, `\u180E`,
+`\u200B`, `\u200C`, `\u200D`, `\u200E`, `\u200F`, `\u202A`, `\u202B`, `\u202C`,
+`\u202D`, `\u202E`, `\u2060`, `\u2061`, `\u2062`, `\u2063`, `\u2064`, `\u2066`,
+`\u2067`, `\u2068`, `\u2069`, `\u206A`, `\u206B`, `\u206C`, `\u206D`, `\u206E`,
+`\u206F`, `\u2E2F`, `\uFEFF`, `\uFFF9`, `\uFFFA`, `\uFFFB`
 
 a|
 label:functionality[]
@@ -157,6 +157,22 @@ dbms.upgradeStatus()
 a| These procedures have been removed from Cypher 25.
 For more information, see the link:{neo4j-docs-base-uri}/operations-manual/current/procedures/[Operations Manual -> Procedures].
 
+a|
+label:functionality[]
+label:removed[]
+[source, cypher, role="noheader"]
+----
+WITH 1 AS g
+RETURN COLLECT {
+        UNWIND [1,2,3] AS x
+        WITH * WHERE x < 0
+        WITH COUNT(*) AS agg
+        RETURN agg + g
+} AS x
+----
+
+a| The xref:subqueries/collect.adoc[`COLLECT`], xref:subqueries/count.adoc[`COUNT`], and xref:subqueries/existential.adoc[`EXISTS`] subquery expressions no longer use imported variables as grouping variables in aggregations.
+
 |===
 
 === Deprecated in Cypher 25
@@ -206,6 +222,16 @@ MATCH SHORTEST $param GROUPS (:A)-[:R]->{0,10}(:B)
 
 a| Parameters can now be used in xref:patterns/shortest-paths.adoc[`SHORTEST` and `ANY` path patterns].
 
+a|
+label:functionality[]
+label:updated[]
+[source, cypher, role="noheader"]
+----
+RETURN $0hello
+----
+
+a| Parameters can start with extended identifier characters, in line with the xref:appendix/gql-conformance/index.adoc[GQL] standard.
+
 a|
 label:functionality[]
 label:updated[]

modules/ROOT/pages/syntax/parameters.adoc

@@ -26,7 +26,7 @@ Parameters cannot be used for the following constructs, as these form part of th
 * Relationship types; `MATCH (n)-[:$param]->(m)` is invalid.
 * Node labels; `MATCH (n:$param)` is invalid.
 
-Parameters may consist of letters and numbers, and any combination of these, but cannot start with a number or a currency symbol.
+Parameters may consist of any combination of letters and numbers, and can start with any of xref:appendix/gql-conformance/index.adoc[GQL's] extended character identifiers.
 
 Setting parameters when running a query is dependent on the client environment.
 For example: