When going to the security tab of your account, you might notice a section called "Restricted image types"
This section refers to the restriction of creating new resources from unsigned requests (like creating derived images on the fly or using unsigned upload presets that create eager transformations) that are associated with that type.
When first subscribing to Cloudinary, certain types may be restricted by default on your account, to protect your quotas from being abused or misused by others. For example URLs of type fetch are automatically restricted with new accounts.
For example when the 'Uploaded' option is selected, only signed upload requests will be approved, and all unsigned requests, like Auto-upload , unsigned uploads, or uploads via our Upload widget (which also uses unsigned uploads), will be restricted.
Those limitations are all customizable via your account security settings page.
"check" a box if you wish to restrict the access to 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.