What are Alias and com.apple.LSSharedFileList.Binding data in sidebsarlists plist

In com.apple.sidebarlist file you can find different CustomListItems for the "Favourites items" in Finder sidebar.

For example:

<dict>
    <key>Alias</key>
    <data>
    AAAAAACmAAMAAQAAzyiimAAASCsAAAAAAAkOewAJDn8A
    AM8oo6IAAAAACSD//gAAAAAAAAAA/////wABAAgACQ57
    AAJl2QAOABQACQBEAG8AdwBuAGwAbwBhAGQAcwAPABoA
    DABNAGEAYwBpAG4AdABvAHMAaAAgAEgARAASABVVc2Vy
    cy9uYWlhZC9Eb3dubG9hZHMAABMAAS8AABUAAgAM//8A
    AA==
    </data>
    <key>CustomItemProperties</key>
    <dict>
        <key>com.apple.LSSharedFileList.Binding</key>
        <data>
        ZG5pYgAAAAABAAAAAAAAAAAAAAAAAAAAAAAA
        AAAAAAAAAAAAZm53ZAIAAAAAAAAA
        </data>
        <key>com.apple.LSSharedFileList.TemplateSystemSelector</key>
        <integer>1935819884</integer>
    </dict>
    <key>Name</key>
    <string>Downloads</string>
</dict>

What are Alias and com.apple.LSSharedFileList.Binding data and how to create your own data ?

I guess they are icons or path to them, but how to generate these data strings, what are the specification for those icons and where do they have to be stored?