is an attribute that prevents values associated with a symbol from being seen.


  • Individual values associated with readprotected symbols can be used during evaluation.
  • Definition[f], ?f, and related functions give only the attributes for readprotected symbols f.


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Basic Examples  (2)

Properties & Relations  (2)

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:

Introduced in 1988