Custom ontologies: unable to create

I am currently planing and testing Omeka S for building an online cassettography. In fact the idea is to move from MediaWiki to Omega S for this project:
Since a lot of the properties we use in this project are not (yet) included in standard ontologies I have to create a new ontology using the module “Custom ontologies”.

But for some reason I was unable to create a new ontology. My steps are the following:

  1. I create a new ontology by entering
    Namespace uri:
    Prefix: tk7
    Label: testk7
    and add a comment;

then I enter a couple of classes and properties I want to create, such as
in the field “Create specific classes”:

and “Create specific properties”


  1. When I finally click on “Get turtle” I get an error message "No ontology exists for prefix “testk7"” for every class and property.

What is my mistake? As far as I understand the explanatory text “The next three forms are independant, and can be used together (for a new ontology)” I should be able to create a new ontology by filling all three forms together. But it looks like I’m overlooking something.
A helpful answer is highly appreciated.

Hi there, it’s been a while since I used this module but I believe you need to use the prefix “tk7” on your class and properties, i.e. “tk7:CassetteAlbums”, “tk7:trackinglist”, “tk7:arrangement”.
Or you should change the prefix in the first part to “Prefix: testk7” instead. I think the label and prefix can be the same.

Hi Allana,

thank you very much for your reply!

I tried it with prefix and label “tk7” and then get an error message for every row like:
" The term “tk7:CassetteAlbums” must have a label."

Yes, you need to include a human-readable label after each term, separated by a comma.

So, you would enter, one line each:
tk7:trackinglist,Tracking List

You can also include comments that help explain what the field is for; I think the comments are optional but you may find an error that declares them to be mandatory too.

So, something like:
tk7:trackinglist,Tracking List,The list of the tracks in order on the cassette, including Side A and Side B designations.
tk7:arrangement,Arrangement,Information about the instrumentation on the cassette.

Tank you very much!!
That was the solution. From the explanation in the module it was not really clear to me that the human-readable label has to be added in that way.
Thank you!