Gerben Wierda via ntg-context schrieb am 23.10.2021 um 15:24:
> On 23 Oct 2021, at 15:15, Pablo Rodriguez via ntg-context 
> <ntg-context@ntg.nl <mailto:ntg-context@ntg.nl>> wrote:
>>
>> On 10/23/21 3:00 PM, Gerben Wierda via ntg-context wrote:
>>> By the way, neither does \blackboard{Q} work. But \rationals works in
>>> the case of the letter Q.
>>
>> Hi Gerben,
>>
>> it only seems to work inside math:
>>
>>  \starttext
>>  \dorecurse{26}{$\blackboard\characters{\recurselevel}
>>  \Characters{\recurselevel}$}
>>  \stoptext
>>
>> I hope it helps,
>
> Yes, the new \blackboard command works, so $\blackboard{Q}$ works. Thanks.

The \blackboard command is a switch like \it, to keep it local to a 
single character put the left brace before the command.

     $Q {\blackboard Q} Q$

Wolfgang