Username with special characters does not work

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**Elasticsearch version:8.12.2

**Server OS version:Centos7

I was using pongo#~!$*()_-+=.?/pongo#~ !$() -+=.?/pongo#~`!$() -+=.?/db18 as user name it is working fine in ES6 but throwing error in ES8.
Thats it.**Elasticsearch version:8.12.2

**Server OS version:centos 7
Search guard version

Error Message
Successfully connected to cluster elasticsearch (localhost) as user CN=Server,
java.lang.IllegalArgumentException: Illegal character in fragment at index 36: /searchguard/internal_users/…username…encripted
at java.base/
at org.apache.http.client.methods.HttpGet.(
at com.floragunn.searchguard.sgctl.client.SearchGuardRestClient.get(
at com.floragunn.searchguard.sgctl.client.SearchGuardRestClient.getUser(
at com.floragunn.searchguard.sgctl.commands.user.UpdateUser.lambda$call$1(
at com.floragunn.searchguard.sgctl.commands.BaseCommand.retryOnConcurrencyConflict(
at picocli.CommandLine.executeUserObject(
at picocli.CommandLine.access$1500(
at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(
at picocli.CommandLine$RunLast.handle(
at picocli.CommandLine$RunLast.handle(
at picocli.CommandLine$AbstractParseResultHandler.execute(
at picocli.CommandLine$RunLast.execute(
at picocli.CommandLine.execute(
at com.floragunn.searchguard.sgctl.SgctlTool.exec(
at com.floragunn.searchguard.sgctl.SgctlTool.main(
Caused by: Illegal character in fragment at index 36: /searchguard/internal_users/…
at java.base/$
at java.base/$Parser.checkChars(
at java.base/$Parser.parse(
at java.base/
at java.base/
… 17 more
Failed to update user. The installation was aborted.
Below username is works in elasticseach 6 but throws error in elasticsearch 8.12.2

I need official documentation where it is written that these special characters in username and password is not

These 4 are invalid when used in username

  1. ?
  2. /
  3. `

I did not get any response please delete my topic .