What's the purpose of login/template/ftl - show-username & attemptedUsername section

[Mark Paxton]

Dear community,

I'm working on a project at the moment where I am customising the keycloak (base) theme with company specific layout, styles, etc. Right now I'm updating everything from earlier versions of keycloak (9/10) to the 13.0.x release.

I came across the show-username and attemptedUsername sections:

https://github.com/keycloak/keycloak/blob/8cd56b37d36c868ff52a351b1e736027bf62aeed/themes/src/main/resources/theme/base/login/template.ftl#L96

I would like to ask the rationale behind this. 

From what I can see, this places content beneath the header including the attempted username as part of the auth process.

I don't understand the reason this is in the general template since it forces extra content on to pages that you might not expect/want, and makes it very hard to remove them. Why not just have a generic section, or put it on the specific page template within the header?

I'm thinking if removing it from my own template implementation, but unless I know why it's there, I am worried about breaking some feature that required it to be done this way!

Help would be really appreciated!

Thanks

Mark