|New Save Dialog|
As the name suggests, One Off Maps let you create quick, single use maps you can email to a friend or post in a forum and then largely forget about. If you're signed in when you create one, it will still be linked to your account so that you can make changes, but it won't show up under your map list. If you don't want to sign in using OpenID, you can enter a password to allow future edits.
Browser Maps store data on your browser using HTML5 local storage. They're not backed up to CalTopo, and there's no way to share them as the data only exists on your computer. However, you can take them with you when you don't have internet access, and then transfer the data back to CalTopo later - more on this when offline maps are made public. The browser map UI looks almost exactly the same as the standard map UI, except that the Share link is missing:
With one off and browser maps done, it was finally time to revisit the "Your Maps" screen. There's now a second table showing your browser maps, and tools to copy maps between CalTopo and your browser:
When you click on the red X, you get two options: delete the map entirely, or turn it into a one-off map. If you still want a link you sent people to work, but don't care about managing it through your account anymore, you can detach it and forget about it: