  Two examples, not connected at present, from author's papers (Nuovo Cim.,
1992, v.105A, p.77 [hep-th/0207210] and GRG, 1999, v.31, p.1431
[gr-qc/0207017]) are considered here in which a physical model has discrete
symmetries and additional non-observable coordinates or parameters. Then it is
possible to introduce some apparent continuous symmetries of the model for an
observer which cannot know values of these additional quantities.
