Questi tipi di errori cosa significano:
Citazione:
Byte-Order Mark found in UTF-8 File.
The Unicode Byte-Order Mark (BOM) in UTF-8 encoded files is known to cause problems for some text editors and older browsers. You may want to consider avoiding its use until it is better supported.
Citazione:
document type does not allow element "ul" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
<ul id="menu_a_2livelli">✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
Citazione:
document type does not allow element "hr" here; assuming missing "li" start-tag
…top: -8px; margin-left: -1495px;" size="0" width="930" noshade="noshade"></hr>
Citazione:
end tag for "li" omitted, but OMITTAG NO was specified
</ul>✉
You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
Per caso si deve chiudere con />...ma cosi verrebbe fuori </ul />
Citazione:
start tag was here
<hr style=" z-index:35px; margin-top: -8px; margin-left: -1495px;" size="0" wid…
Citazione:
document type does not allow element "hr" here; assuming missing "li" start-tag
…top: -8px; margin-left: -1495px;" size="0" width="930" noshade="noshade"></hr>
Citazione:
document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
…style="margin-left:18px; width:120px;"><a href="Febbraio_cure_alle_piante.html…✉
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.
One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").