Last time, I wrote a column called "Points to be aware of when migrating to a site without losing the SEO effect ". This time, I would like to industry email list introduce the points when migrating a smartphone site. This is a sequel to the previous article, so please read it together with the previous article. table of contents Points to note on sites for industry email list multiple devices Vary HTTP header Annotation settings Implementation on the site Points to note on sites for multiple devices. For sites that support multiple industry email list devices such as those for PCs, smartphones, and feature phones, there are two points to industry email list pay particular attention to. Vary HTTP header Annotation settings It is not always necessary to implement all of these, and what you need depends on the format of the site provided for each device. We will introduce the contents of each item. Vary HTTP header Roughly industry email list speaking, the Vary HTTP header is an HTTP header that expresses the information that "this page (URL) changes depending on ◯◯" when returning the content from the server. Actually, I think that industry email list most of the content is sorted by the user agent, so I will introduce an example of the setting. (When using Apache mod_header) Header set Vary User-Agent Add it to the Apache configuration file or .htaccess.