Here, the solution is to replace “rel” with “class”.So when you want to trigger lightbox, use this code: Notice how rel=”lightbox” has been changed to class=”lightbox”. We also have to edit the Java Script file to switch the trigger from “rel” to “class”.Facebook’s Open Graph protocol is an awesome tool that allows you to control the appearance of content that gets “liked” from your site on Facebook.Unfortunately, the meta syntax that makes this work does not validate in HTML5 and probably never will (here’s hoping…).Instead of just typing out “&” use the following code in your webpages: For a full list of symbols and their HTML entity equivalent visit W3Schools’s Entity List.This actually only applies when using XHTML, but it’s usually a good habit to get into. In other doctypes it is perfectly acceptable to add a line break with: Other common self-closing tags include (but are not limited to) meta, input, area, and hr.All pages in the City of Cranston website should validate as proper XHTML 1.0 Transitional code.However, the content of the website is dynamic, and as such, certain dynamic elements may fail to validate (for example, if an ampersand is entered into certain areas instead of the proper HTML escape sequence for an ampersand).
Now this is a very common error that is not specific to HTML5, but luckily it’s very easy to fix!
The CSS file that calls these workarounds uses Internet Explorer-only code, and thus may not validate properly.
All web designers should validate their site using W3C Markup Validation Service. Simply put the link to your website in the box (or use the file upload or direct input options) and press “Check.” The service will then scan your markup to find any errors according to the doctype you selected.
If you use Lightbox your code will not validate for HTML5.
In order to trigger the lightbox effect you have to embed rel=”lightbox” into your link. It’s the same issue with rel keywords as above, but the solution is a little different.