User registration is not mandatory, but users wanting to have additional functionalities, like access to previous analyses, have the possibility of opening a user account.
In economic terms, every new mandatory disclosure, user control, and privacy "dashboard" introduces transaction costs into interactions that previously didn't have them.
Version 6 was not mandatory, but users apparently saw little reason to move on to newer software.
In August, Facebook experienced a backlash after it made its Messenger app mandatory for users in the US, requiring a long list of permissions for the Android version including access to audio recordings, photos and videos, phone numbers, text messages and contacts, as well as almost thirty other functions.
However, this assignment is not mandatory and user-defined mechanisms can use different configurations.
It's not mandatory, but users can edit video properties from their phone, such as title, tags, category, and access rights (public or private).
Nowadays, package leaflets are mandatory, more user-friendly, and numerical frequencies have become an obligatory supplement to verbal descriptors [ 15, 16].
In this regard, it should be noted here that it is not mandatory that a user at SO must make his/her location public.
Likewise, there's App World for Work, a special enterprise-specific version of BlackBerry's mobile application marketplace that can serve only apps hosted on a company's own servers, or provide access to certain white-listed apps selected or made mandatory by the user's employer.
