Sorry, I am unable to validate this document because its content type is application/octet-stream, which is not currently supported by this service.
The Content-Type field is sent by your web server (or web browser if you use the file upload interface) and depends on its configuration. Commonly, web servers will have a mapping of filename extensions (such as ".html") to MIME Content-Type values (such as text/html).
That you received this message can mean that your server is not configured correctly, that your file does not have the correct filename extension, or that you are attempting to validate a file type that we do not support yet. In the latter case you should let us know that you need us to support that content type (please include all relevant details, including the URL to the standards document defining the content type) using the instructions on the Feedback Page.
a jeżeli dam stronkę na serwer to pisze:
No Character Encoding Found! Falling back to UTF-8.
I was not able to extract a character encoding labeling from any of the valid sources for such information. Without encoding information it is impossible to reliably validate the document. I'm falling back to the "UTF-8" encoding and will attempt to perform the validation, but this is likely to fail for all non-trivial documents.
Read the FAQ entry on character encoding for more details and pointers on how to fix this problem with your document.
Sorry! This document can not be checked.
Sorry, I am unable to validate this document because on line 58-60, 65, 70-71, 74, 76, 80 it contained one or more bytes that I cannot interpret as utf-8 (in other words, the bytes found are not valid values in the specified Character Encoding). Please check both the content of the file and the character encoding indication.