A Wikiversity custodian is an experienced and trusted user who can protect, delete and restore pages as well as block users from editing. On other Wikimedia projects, custodians are also known as admins, sysops, bibliotecarios (librarians), and moderators.
How does one become a custodian? 
Any Wikiversity participant willing to do a lot of dull and boring work for the community can become a custodian. If you have a good editing record then you are likely to be trusted and granted the privileges and responsibilities of custodianship. If you are still interested in custodianship, here is the process it takes:
You must request or be nominated for custodianship at Candidates for Custodianship. State your reasons for seeking this position and in what areas you are or would like to be active. You may also refer to your contributions and indicate whether you have similar responsibilities at other projects.
Custodian mentors are expected to guide and advise you on the appropriate use of custodian privileges in accordance with established policy and community consensus. If any experienced custodians agree to mentor you and you agree to their mentorship, then you will be approved as a probationary custodian for a period of at least four weeks. You will have all the privileges described below. If you have any questions or concerns, you should contact your mentor(s) for guidance and advice. If you or your mentor terminate the mentorship agreement before the probationary period is complete, you will have 48 hours to find a new mentor. Otherwise your mentor may request removal of custodian privileges after 48 hours, without any further notice or community discussion.
Your mentor will submit a request for comments at Candidates for Custodianship for a period of at least seven days when you are ready. During that period Wikiversity participants can evaluate how well the custodian privileges are used and how you conducted yourself at Wikiversity.
After one week of evaluation, a bureaucrat will make the final decision based on the arguments provided in the discussion. If you are approved, you will be a permanent custodian. If you are not approved, your probationary period may either be extended or you may request another mentorship later.
What can custodians do? 
Deletion and restoration of pages 
Deleting a page does not actually remove it from the database. It is merely invisible to non-custodians and can be restored at request, which may be submitted at Wikiversity:Requests for Deletion. Page deletions and restorations can be monitored by viewing the deletion log.
Custodians can also delete individual versions of a page. This is particularly useful to remove materials that violate copyrights or other applicable law.
Edit and move protection of pages 
Custodians can protect pages to prevent editing. There are two types of page protection: semi-protection, which prevents anonymous and new users from editing, and full protection, which prevents all non-custodians from editing. A page can also be protected to prevent moving. Page protection can be lifted by any custodian upon request, which may be submitted at Wikiversity:Request custodian action. Page protections and unprotections can be monitored by viewing the protection log.
Custodians have a rollback tool to revert the last change or group of changes made to a page by the same user. There is no option to provide an edit summary when using this tool. Instead, a text similar to "Reverted edits by User:Foo; changed back to last version by User:Bar" will be used automatically. This tool is primarily used to respond to obvious vandalism. For other edit reversions, the rollback button should not be used and a good edit summary should be provided.
User blocks 
Custodians can block users from editing by specifying a username, an IP address or range of addresses. Blocks can be temporary or permanent. Most frequently, blocking occurs in response to obvious and repeated vandalism. When blocking a user, a reason for blocking must be provided which is displayed in the block log. It is also possible to block IP addresses from creating new user accounts. See Wikiversity:Blocking policy.
Custodians are able to edit the standard texts that are used by the MediaWiki software. Examples of these texts are the aforementioned message for reverts and the global and skin-dependent style sheets.
Custodians have access to the Import tool, to bring materials from Wikipedia, Wikibooks, Beta.Wikiversity, Wikiquote, and Wikisource.
How are Custodians expected to act? 
Custodians are supposed to follow the same principles as every other user, including being civil, assuming good faith, and understanding what Wikiversity is. They are expected to act professionally, and to respect policy and community consensus.
For a discussion of possible failure to act professionally, see a proposed recusal policy at Wikiversity:Recusal.
Problems with Custodians 
If you have a question about an action (page deletion, page protection, user block, editing MediaWiki namespace pages, violation of Wikiversity policy or some other action that does serious damage to the project) by a Wikiversity custodian, the first thing to do is leave a message on that custodian's user discussion page. Custodians should always be able to explain how their actions support the Wikiversity project. If you cannot get satisfaction from discussion with the custodian, you can place comments, suggestions, complaints or questions at Wikiversity:Custodian feedback. Try to resolve all custodian problems by discussion.
Custodians can lose their status for egregious violations of policies. Loss of custodianship involves a process that establishes community consensus. If a specific complaint is not resolved at Wikiversity:Custodian feedback then a new seven day community discussion can be initiated to establish if there is community consensus in support for the custodianship of the custodian who is the subject of the unresolved complaint. At the end of that seven day period of community discussion, Wikiversity bureaucrats will review the discussion. If a bureaucrat decides that there is good reason for removal of a custodianship, that bureaucrat will go to the meta-wiki and request that stewards review the community discussion. If a steward agrees that the Wikiversity community has reached consensus about a problem custodian, then that steward can terminate the custodianship of the custodian.
If you have a question about an action of a probationary custodian, you should consult their mentor(s). Actions of a probationary custodian are the responsibility of their mentor(s) during their probationary period. Partially depending on agreements made in the probationary candidacy, and with respect for the 48 hour period to find a new mentor, a request to remove custodianship for a probationary custodian may often be made at Meta by any mentor or bureaucrat without need for community consensus. The local process to remove custodianship should only need to be used as a last resort, because of this alternative option.
- Custodianship is a responsibility, not a right. While everyone is encouraged to apply for custodianship, the position is not suited for everyone. Please also note that in all instances not listed above, custodians have no more power or weight than other users. "Custodianship is not a big deal."
- Custodians should set their "user preferences" so as to provide for email contacts from other Wikiversity participants. If you do not use email, then you must make yourself easily available by some other means such as IRC chat.
Useful reads for Custodians 
- Wikiversity:Blocking policy
- Wikiversity:No shrines for vandals
- Wikiversity:Revision deletion
- How to be a Wikimedia sysop/Wikiversity