These are some of the reasons why Google might give you a policy violation reply.
-Valuable inventory: scrap content: Google doesn't like a page that copies people's content and then paste to oneself. they love unique and quality content that can make users engage. they won't allow you to place ads on pages that have plagiarized contents. scrap content can also be when you embed videos, images, or other media from the different website without you adding any value to your visitors
To resolve this issue, remove all copied content from your website and write unique content, focus on the originality of the content, write long articles if possible and this policy won't is given to you no more.
-Valuable inventory: no content; this kind of violations do happen when you are trying to place google ads on a page that has little content or no content at all, this can also be when trying to show ads on login pages or registration pages, these pages are not useful to Adsense for ads, because it doesn't have content on it. there are a lot of people who are trying to game Google, but these people are smarter than you think, I'll advise you to kindly remove those pages or write better more content, or better still remove ads from showing there totally.
-Valuable inventory: Under construction; when I started with blogging, I got this notice always and it was really annoying because I had no idea what it meant. Google Adsense did not actually explain what it means properly to me and I had to do some little experiment just to find out what this under construction means. basically it so obvious it means your website is still under construction, but on the other hand, it does relate to how many unique posts you got. for example, if you have 10 post that is not unique, its will be flagged as under construction but if you have just 5 unique and well-written article, it will show that advertisers would rather put their own ads in that website with 5 articles with unique content and also make sure you have some recent post too to show activity on your website and yeah Google will definitely approve you only if you don't violate other policies.
-Valuable inventory: templates page; this kind of message goes with your website quality, it can be different reasons like your website homepage is not properly designed, you don't have a good theme or if you do, maybe you are not designing it properly to be friendly use. another reason can be broken links, or your menu bar doesn't have a link at all. there are so many reasons to this so you just have to be careful when designing your themes, it also can be if the content is either repeated within the page or is just copied or mirrored from other site. and yeah with the whole thing, don't make your navigation poor.
These are just some of the policies I know and will update if I fully understand other inventory. if your problem is listed above, here you go, fix your thing !!!!!!!
