You can add application-wide HTML tags to your application’s master pages. These master page files are used as the basis for most of your application’s web pages. This approach saves you from manually adding them to every page in your application. Your application’s master pages are located the Master Pages folder, e.g.:
...\MyApp\Master Pages\HorizontalMenu.master
Step 1: Locate the master page file, e.g.:
...\MyApp\Master Pages\HorizontalMenu.master
Step 2: In Layout Editor, open the Page Directives dialog (Property Sheet, Page section, Page Directives…).
Step 3: Add your ‘application-wide’ tags in the HTML’s <head> section of the master page file via the Page Directives dialog, e.g.:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title> </title>
<meta name="keywords" content="My Keywords">
<meta name="description" content="My Description">
<link rel="stylesheet" rev="stylesheet" type="text/css" href="../Styles/Styles.css"/>
</head>
Step 4: Rebuild your application (Build, Rebuild All).
The new tags will be included on every page that references the updated master page.