These are custom bookmarklets that have some functionality added. To use them, follow the same procedure as with the default bookmarklet.
"read later" bookmarklet
This bookmarklet will automatically tag the sites you historify as unread. When you visit the site from within historious, the unread tag will be removed. This will remove the site from your "read later" list.
This bookmarklet will prompt you to add tags when historifying.
This bookmarklet will automatically add tags when historifying. Use this if you want to quickly historify some pages with a tag. For example, if you want to always tag some things as "work", you can use this bookmarklet to do that automatically. You should still keep the original bookmarklet, in case you don't want to tag a site.
To add your tags, you will need to right-click on the bookmarklet (after you have added it to your browser) and click "Properties" (or another, similar menu item). There, just replace the text 'tag1, tag2, tag3' (but leave the quotes) with your own tags. If it doesn't work, remove it and try again!