Mild Error character length goes beyond the recommended 150 characters
When possible, the H1 tag is to not exceed more than 150 characters, including spaces. It is to act like the headline of the copy - precise and descriptive.
An H1 tag is an indicator of what the body copy is about. The H1 tag should be a precise description of what is to be expected in the body of the page. Try not to exceed 150 characters in the H1 since it is a headline (title) for the page text. Recommend: Use an H1 tag that includes keywords that reflect the contents of the page and keep it within 150 characters.
Little Error More than 5 in total of <H2>, <H3>, <H4>, <H5> and <H6> tags exist in the source code
Only H2-H6 tags are valid fo indicating content segregation
Search Engines treat the H2-H6 tags as an indicator or content seperation. For example, the H2 tag could be used for sub-sections of an article and H3 for sub-sub sections of the same content.
Mild Error multiple <H1> </H1> tags are found in the source code
ONLY ONE H1 per page. Remove extra <H1> tags
Only ONE H1 PER PAGE. An H1 tag is utilized as a indicator of what the body copy is about. Multiple H1 tags are considered a bad practice by search engines, and the value of the page will be diminished. If there is an overuse of H1 tags on several pages, they will be determined to be junk pages and may be not be indexed at all. Detail: H1 tag reinforces the core keyword-phrase for a page, which is targeted in the <TITLE> and META DESCRIPTION tags and in combination with them improves page relevancy and search engine ranking. Recommend: Use an H1 tag that includes keywords that reflect the contents of the page. Search engine crawlers expect to find only one H1 tag to analyze for page relevancy.