Just read the phrase the following way
 
"A name is exported by a module if it is introduced or redeclared by an exported
declaration in the purview of that module."
 
This phrase contradicts the previous phrase that makes the reading is entirely unclear.
 
 
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>Четверг, 17 февраля 2022, 1:33 +03:00 от Jason McKesson via Std-Discussion <std-discussion_at_[hidden]>:
>
>On Wed, Feb 16, 2022 at 5:11 PM Vladimir Grigoriev via Std-Discussion
>< std-discussion_at_[hidden] > wrote:
>>
>> What is the difference between these two phrase
>>
>> An exported redeclaration of a non-exported declaration of an entity is ill-formed.
>>
>> and
>>
>> A name is exported by a module if it is redeclared by an exported declaration in the purview of that module.
>The second phrase does not appear in the C++20 standard (at least not
>N4861, nor the current working draft). In N4861, we see "A name is
>exported by a module if it is introduced or redeclared by an exported
>declaration in the purview of that module." in section 10.1/7. So
>there doesn't seem to be a problem here; the wording is a bit
>imprecise (since it's not possible to redeclare an entity as exported
>if it was not introduced as exported), but still valid.
>
>For what it's worth, the current working draft doesn't even bother
>with that statement, relying entirely on 10.1/2 for what it means to
>export something.
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