Within SharePoint 2013, as there was with 2010 & 2007, there are a multitude of GUIDs everywhere – for Sites, Lists, Fields and so forth.
When using these inside a feature, like a custom Content Type and/or Field Ref, it can be a little tricky to determine the GUIDs.
There are a number of places you can grab the URL, and the LIST GUID is within the QueryString – but can be tricky if they are ‘encoded’.
I’ve found a very useful site that does a quick encode/decode – just need to paste in the text.
Another scenario is within SharePoint Designer, and needing to work with a DataViewWebPart – when you save this out to a .WEBPART, there is a “CDATA” section that is encoded.
Usually (in the past) I’ve had to change the < into <, and the > into >.
But – can now just past the whole slab of text into the “DENCODER”.
Thanks a lot Eric Meyer…!