What's the meaning of the percent sign in variable names

[Luis Felipe]

Hi,

Are all these constants (%base-packages, for example)? Is this a Guix 
convention or does it come from Guile? Although looking at Guile's Variable 
index I see many constants in uppercase, and also some variables prefixed with 
the percent sign, while Guix' Programming index doesn't seem to list any 
uppercase names.


Thanks,

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Luis Felipe López Acevedo
https://luis-felipe.gitlab.io/