The document is here . What does "restricted indices" meas in "allow_restricted_indices" params?

What does "restricted indices" means in Security:Has privileges API?

LoadingZhang (Lucas Zhang) June 12, 2019, 3:27am 3

Thanks for reply.
I hope we can customize restricted indices in the future.

Topic		Replies	Views
Indices Restrictions Elasticsearch	2	685	March 9, 2017
User permission control on the indexes Elasticsearch	2	308	July 6, 2017
Access user to access particular index in shield Elasticsearch elastic-stack-security	4	1173	July 6, 2017
User Not Permitted to Check If Index Exists Elasticsearch elastic-stack-security	4	2241	July 29, 2019
How to prevent access to specific indexes? Elasticsearch elastic-stack-security	3	2320	July 6, 2017