Create NU1508 (#3333)

Author: zivkan

docs/TOC.md

@@ -183,6 +183,8 @@
 ### [NU1504](reference/errors-and-warnings/NU1504.md)
 ### [NU1505](reference/errors-and-warnings/NU1505.md)
 ### [NU1506](reference/errors-and-warnings/NU1506.md)
+### [NU1507](reference/errors-and-warnings/NU1507.md)
+### [NU1508](reference/errors-and-warnings/NU1508.md)
 ### [NU1601](reference/errors-and-warnings/NU1601.md)
 ### [NU1602](reference/errors-and-warnings/NU1602.md)
 ### [NU1603](reference/errors-and-warnings/NU1603.md)

docs/reference/Errors-and-Warnings.md

@@ -43,7 +43,7 @@ NuGet supports the following configuration properties.
 
 | Group | Warning numbers |
 | --- | --- |
-| Invalid input warnings | [NU1501](./errors-and-warnings/NU1501.md), [NU1502](./errors-and-warnings/NU1502.md), [NU1503](./errors-and-warnings/NU1503.md), [NU1504](./errors-and-warnings/NU1504.md), [NU1505](./errors-and-warnings/NU1505.md), [NU1506](./errors-and-warnings/NU1506.md), [NU1507](./errors-and-warnings/NU1507.md) |
+| Invalid input warnings | [NU1501](./errors-and-warnings/NU1501.md), [NU1502](./errors-and-warnings/NU1502.md), [NU1503](./errors-and-warnings/NU1503.md), [NU1504](./errors-and-warnings/NU1504.md), [NU1505](./errors-and-warnings/NU1505.md), [NU1506](./errors-and-warnings/NU1506.md), [NU1507](./errors-and-warnings/NU1507.md), [NU1508](./errors-and-warnings/NU1508.md) |
 | Unexpected package version warnings | [NU1601](./errors-and-warnings/NU1601.md), [NU1602](./errors-and-warnings/NU1602.md), [NU1603](./errors-and-warnings/NU1603.md), [NU1604](./errors-and-warnings/NU1604.md), [NU1605](./errors-and-warnings/NU1605.md), [NU1606](./errors-and-warnings/NU1108.md), [NU1607](./errors-and-warnings/NU1107.md) |
 | Resolver conflict warnings | [NU1608](./errors-and-warnings/NU1608.md) |
 | Package fallback warnings | [NU1701](./errors-and-warnings/NU1701.md), [NU1702](./errors-and-warnings/NU1702.md), [NU1703](./errors-and-warnings/NU1703.md)|

docs/reference/errors-and-warnings/NU1508.md

@@ -0,0 +1,26 @@
+---
+title: NuGet Warning NU1508
+description: NU1508 warning code
+author: zivkan
+ms.author: zivkan
+ms.date: 08/10/2024
+ms.topic: reference
+f1_keywords: 
+  - "NU1508"
+---
+
+# NuGet Warning NU1508
+
+## Scenario 1
+
+> Duplicate 'NuGetAuditSuppress' items found. Remove the duplicate items or use the Update functionality to ensure a consistent restore behavior. The duplicate 'NuGetAuditSuppress' items are: https://contoso.test/cve/1 , https://contoso.test/cve/1 .
+
+### Issue
+
+Sometimes when adding `NuGetAuditSuppress` items, you may end up adding an item for a particular package multiple times.
+
+MSBuild projects commonly import multiple `.props` and `.targets` files, so the duplicates might not be in the same file, but may be in included files, such as `Directory.Build.props`, `Directory.Packages.props`, or `Directory.Build.targets`.
+
+### Solution
+
+Remove the duplicate item, so that it's included exactly once.