I have a transparent iframe on my site and I'm using the allowtransparency="true" tag. However, it doesn't validate in the W3C validator. It's the only thing stopping me from having a valid page Is there a way to have a transparent iframe that validates or something with a similar effect?

Any help or information is appreciated. Thanks in advance

It depends on which doctype you checking against. The allowTransparency is a valid property for the iframe but not allowed for every doctype.

When you for example want to make it validate against xhtml then the only way to archive this is by adding the attribute with some JavaScript code, that is probably not the most preferable solution but the only one to get it validated.