## WebUtility.HtmlEncode and WebUtility.HtmlDecode round-trip BMP correctly

### Scope
Edge

### Version Introduced
4.5

### Source Analyzer Status
Planned

### Change Description
For applications that target the .NET Framework 4.5, characters that are outside the Basic Multilingual Plane (BMP) round-trip correctly when they are passed to the WebUtility.HtmlDecode method.

- [x] Quirked
- [ ] Build-time break

### Recommended Action
This change should have no effect on current applications, but to restore the original behavior, set the targetFramework attribute of the `<httpRuntime>` element to a string other than "4.5". You can also set the `unicodeEncodingConformance` and `unicodeDecodingConformance` attributes of the `<webUtility>` configuration element to control this behavior independently of the targeted version of the .NET Framework.

### Affected APIs
* `M:System.Net.WebUtility.HtmlEncode(System.String)`
* `M:System.Net.WebUtility.HtmlEncode(System.String,System.IO.TextWriter)`

### Category
ASP.NET

[More information](https://msdn.microsoft.com/en-us/library/hh367887(v=vs.110).aspx#asp)

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    ### Notes
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