Unique Content
In consideration of my external linking policy I am surprised that any website allows links to other websites.
Looking on my page describing Search Engine Results Pages I realised that there was no real unique information on it. I hadn't even linked to this page, in fact I hadn't even upload this page! As I am in the process of checking my pages, whether they pass validation and if they are in the Google Index, I have found that some pages are indexed while others are not even if they have been found by the Google Searchbot, googlebot.
The unique content
This is information that I have discovered for myself and techniques that I have developed. Historical research and interpretations on what I have found.
When to request a page is (Re)Indexed
There is no point if the page has not sufficient unique content.
The precess of validation and checking whether the page has been indexed by Google are part of this exercise. If a page is indexed by Google it is likely that the other search engines, such a Bing, have also indexed it. Analytics will also give you a clue to this as you will be getting hits (clicks) that don't have the corresponding Impressions as recorded in the Search Console. The Search Console will only tell you whether page was found in a Google SERP and whether it was high enough and interesting enough for the person making the search to click on.