19.64 - index should not require unique values -> may require unique values?

Greetings,

A niggle over 19.64 - index should not require unique values -> may
require unique values?

I read the "should" as recommended positive practice, that is stronger
than the suggested "may."

Is there a difference or would "may" suffice?

It reads better with "may" but wanted to ask.

Hope everyone is having a great week!

Patrick

-- 
Patrick Durusau

Technical Advisory Board, OASIS (TAB)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)

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