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- '1' (one) and 'l' (lower case el)
- '0' (zero) and 'O' (capital o)
- '2' (two) and 'Z' (capital Z)
- '5' (five) and 'S' (capital S)
- '8' (eight) and 'B' (capital B)
Do not define multiple identifiers that vary only with respect to one or more visually similar characters.
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