When submitting the app to the windows phone store it fails the review with the following encoding issues.
FAILED - UTF-8 file encoding
"Error Found: The UTF-8 file encoding test detected the following errors:
File tizen-iap.js is not properly UTF-8 encoded. Re-save the file as UTF-8 (including Byte Order Mark).
File channel.html is not properly UTF-8 encoded. Re-save the file as UTF-8 (including Byte Order Mark).
File bubblegum.css is not properly UTF-8 encoded. Re-save the file as UTF-8 (including Byte Order Mark).
Impact if not fixed: HTML, CSS, and JavaScript files must be encoded in UTF-8 form with a corresponding byte-order mark (BOM) in order to benefit from bytecode caching and to avoid other runtime error conditions.
How to fix: Open the affected file, and select "Save As..." option from the File menu in Visual Studio. Select the drop-down control next to the Save button and select "Save with Encoding..." option. From the Advanced save options dialog, choose the "Unicode (UTF-8 with signature)" option and click the OK button."
Of course its easy to fix by the developer but it would be better if they didn't have to tweak these files. bubblegum.css is a font file which was imported into the project so it it is debatable if files should be encoded on import.