If one has a html page, containing the following header metadata
<meta name="verify-v1" content="zt4iF7PprGKc1V9M3J+GxTapeNoh98RJhf0yl5o7zLc=" />
then the following is shown:
Warning 5 Validation (XHTML 1.0 Transitional): This attribute requires a value. If the value is enclosed in quotation marks, the quotation marks must match.
If the following meta tag is used (without the = at the end) the warning is not produced:
<meta name="verify-v1" content="zt4iF7PprGKc1V9M3J+GxTapeNoh98RJhf0yl5o7zLc" />