reasonably visible

, in relation to a specified feature, and for the purposes of Clause F6, means that the specified feature is visible to a person who—
(a) is 10 metres from it, or the greatest distance from it that it is possible to go in the open space surrounding it, whichever is the lesser; and 
(b) has sight that is not defective, or is corrected (for example, by an optical appliance)

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