The platform Brilliant Directories designed offers many features (dynamic or static) for using and manipulating SEO settings, variables, relating SEO data and more. All of this can change depending on many factors, so with all of this moving parts, it is hard to keep track on which SEO variables are used on each individual page, on each individual membership feature, on each content page, on each default or customized member profile, search result, event, photo or photo album, article and more. The system was build in a way that it offers you multiple ways of customizing each individual part of the system, giving you the freedom to make many changes and adapt the system to your needs.
Not all SEO variables are used in specific pages, even more, some only exist on very specific places because they depend on the page type (eg: Content, data_category, account, etc...). This would create a very difficult situation if you want to start working on your SEO settings in an advanced way, even if by default many SEO variables are correctly handled.
For example, there are 3 levels of SEO you can use in regards to Members: SEO Templates, SEO Pages, SEO Members.
The top most SEO level would be the SEO Templates found under the Content option in the Custom SEO Settings as shown in the image below. Here you can change the overall SEO template for all members, categories, pages and more of your site that use it. This affects the whole system.
The following SEO level is the Page SEO Settings. This will affect the SEO for that specific page and any data inside of it, be it members, features and more. This only affects anything inside that page. The Page SEO has higher priority than the SEO Template.
Lastly you have the Member SEO Settings. This will only affect that specific member. For example, how their profile page looks, what SEO settings they have working or disabled, even their custom URL (eg:http://www.mysite.com/united-states/florida/carpenters/steve-wonders could be changed to http://www.mysite.com/stevewonders etc.. The Member SEO has higher priority than the Page SEO and the SEO Template.
With this information I can also add that, by changing the profile SEO template, it will also change for old and new users. If you see it does not work correctly, I recommend clearing the cache of your site by clicking on Developers >> Refresh Cache:
Last tip is that all SEO variables must be within the Percent sign "%". So this is correct %full_name%, but this is not full_name.
This is because All SEO variables on the system are handled with the %% metacharacters.