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is an attribute which prevents values associated with a symbol from being seen.
  • Individual values associated with read-protected symbols can be used during evaluation.
  • Definition[f], ?f, and related functions give only the attributes for read-protected symbols f.
Definitions of a read-protected symbol are not shown:
As long as the symbol is not locked, the read protection can be removed:
If a symbol is locked and protected, its definitions can be neither changed nor read:
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