Gmail – What Does ‘Stay Signed In’ Mean on Login Page?

If you are using a browser that supports multiple tabs then you can open another tab and sign into Gmail in that tabbed window. Then you’ll be implicitly signed in on the tabbed window where you are composing the email, and you’ll be able to save or send it as required.

You can also recreate the condition that you originally discovered by opening two tabbed windows, signed into Gmail. Then start composing an email in one window and sign out of Gmail in the other tabbed window. That will put your composing email tabbed window into the state that you originally discovered (and you can recover it using the above technique).

When you log in, the system wants to know if it's a valid account or whether it should kick you back to the login screen.

According to Mike Sego, a former Gmail engineer, "shva" is an acronym for "should have valid authentication". Apparently, the parameter is only included after a successful authentication.

The 1 is the default value applied to the parameter check. It's also a shorthand way for programmers to say true, like when you have successfully logged in.

The other part, #inbox, tells Gmail to load up your inbox as the first screen. You can change that to one of the other folders (or even labels you've created) to load them up.

E.g., https://mail.google.com/mail/?shva=1#sent will show your Sent folder items.
https://mail.google.com/mail/?shva=1#label/narwhals will load up your "narwhals" label.

Gmail, like many web services, serves a standard interface that will change to show only your information and data when you've logged in.

The particulars are referenced on their end through the use of an ID from the cookies or sessions generated after the login screen.