I have a user control that lets the editor pick which level of heading to use (e.g. h2 if the information supplements the main article, strong/span if it doesn’t). Headings are stored as items in a configuration folder, with a single-line text field for the heading type (e.g. h1) and one for a CSS class. The final output looks like this:

<h2 class="heading">My text</h2>

However, when I load a page up in Page Editor, I get this:

Because the heading type and class fields are going through FieldRenderer, Sitecore thinks that they should be editable. To stop this from happening, disable web editing:

FieldRenderer.Render(HeadingType, "Element", "disable-web-editing=true");

— OR —

<sc:Text Field="Heading" DisableWebEditing="true" runat="server" />

Those fields are no longer editable, but the actual heading text is:

You might also want to do this to the page title and meta description in the page head.