Manual:$wgPasswordSalt

Authentication: $wgPasswordSalt
For compatibility with old installations set to false.
Introduced in version:Before 1.1.0
Deprecated in version:1.24.0 (Gerrit change 77645; git #95a8974c)
Removed in version:1.34.0 (Gerrit change 522574; git #2e909bcb)
Allowed values:(boolean)
Default value:true

Details

For security, the user password hashes include "salt" to make it more difficult for someone who somehow gets hold of the hashes to crack them all at once.

For compatibility with old (pre 1.1.0) installations set this to false.