There might be other Shozammers, who like me have only limited experience of HTML coding and who have surrounded their
Shozam Galleries with pages of their own creation. In looking for advice on how to optimise sites to make them more search engine friendly I came across www.analyzerhq.com/en/
This site requests the entry of your web page URL and will assess, score it and offer suggestions for improvements.
There may be other similar sites to this one but I found the presented information very helpful when told about my missing Doctype and meta tag statements.
Regards
Bartynor