When you upgrade your resource strings to Unicode, don’t forget to specify the L prefix

# When you upgrade your resource strings to Unicode, don't forget to specify the L prefix - The Old New Thing Source: [https://devblogs.microsoft.com/oldnewthing/20260507-00?p=112307](https://devblogs.microsoft.com/oldnewthing/20260507-00?p=112307) May 7th, 2026 3 reactions  Some time ago, I discussed how[the Resource Compiler defaults to CP\_ACP, even in the face of subtle hints that the file is UTF\-8](https://devblogs.microsoft.com/oldnewthing/20190607-00/?p=102569)\. After yet another incident of[Visual Studio secretly changing the file encoding from 1252 to UTF\-8](https://devblogs.microsoft.com/oldnewthing/20241231-00/?p=110696)and breaking all non\-ASCII strings, combined with[Azure DevOps and Visual Studio simply ignoring encoding changes when showing diffs](https://devblogs.microsoft.com/oldnewthing/20241230-00/?p=110692), a colleague decided to solve the problem once and for all by using explicit Unicode escapes\\x\#\#\#\#to represent non\-ASCII characters\. That way, it doesn’t matter whether the file encoding is 1252 or UTF\-8 because the two code pages agree on the common ASCII subset\. What used to be ``` IDS_AWESOME "That’s great!" ``` was changed to ``` IDS_AWESOME "That\x2019s great!" ``` Unfortunately, the resulting string that appeared on screen was > That 19s great\! What went wrong? If you are encoding Unicode into your string, you have to put an`L`prefix on the quoted string\. Otherwise, the\\xABCDsequence is interpreted as an 8\-bit\\xABescape sequence, followed by two literal charactersCD\. In this case, the\\x2019was interpreted as\\x20\(which encodes a space\) followed by the literal characters19, resulting in the stringThat␣19s great\!\. The correct conversion includes the`L`prefix\. ``` IDS_AWESOME L"That\x2019s great!" ``` ### Category ### Topics ## Author  Raymond has been involved in the evolution of Windows for more than 30 years\. In 2003, he began a Web site known as The Old New Thing which has grown in popularity far beyond his wildest imagination, a development which still gives him the heebie\-jeebies\. The Web site spawned a book, coincidentally also titled The Old New Thing \(Addison Wesley 2007\)\. He occasionally appears on the Windows Dev Docs Twitter account to tell stories which convey no useful information\. ## Read next ## Stay informed Get notified when new posts are published\. Follow this blog - [https://twitter.com/ChenCravat](https://twitter.com/ChenCravat) - [](https://www.youtube.com/playlist?list=PLlrxD0HtieHge3_8Dm48C0Ns61I6bHThc) - [https://github.com/oldnewthing](https://github.com/oldnewthing) - [https://devblogs.microsoft.com/oldnewthing/feed/](https://devblogs.microsoft.com/oldnewthing/feed/)