When going to the security tab of your account settings, you may notice a section called "Restricted media types"
This section refers to the restriction of creating new resources via unsigned requests, that are associated with that type.
When first subscribing to Cloudinary, certain types may be restricted by default on your account, in order to protect your account and quotas from being abused or misused by others. For example, URLs of type fetch - when a new account is created, if 'Fetch' has not been used in the account for one week, it will automatically be restricted. Another example is the 'Resource list' type, which relates to our client-side resource list.
Consider the 'Uploaded' option for example - when the 'Uploaded' option is selected, only signed upload requests will be approved, and all unsigned requests, like Auto-upload, unsigned uploads via the API, or unsigned uploads via our Upload widget, will be restricted.
Those limitations are all customizable via your account security settings page.
"check" a box if you wish to restrict access to a certain type of feature and "uncheck" to allow it. Note that while changes in settings take effect immediately, broken URLs may be temporarily cached on the CDN.
Note that these restrictions are only enforced when accessing non-existing assets (pre-existing ones will still be available).
Also note that this restriction can always be bypassed using signed URLs, even if the specific type is checked.