Sufi craft guilds could have shielded persecuted Muslims but left no trace.

Evidence

One might well have thought that already in the Iberian Peninsula such guilds would have provided a highly suitable social mechanism to enable Muslims to cope clandestinely with the persecutions to which they were subjected in the sixteenth century, but we hear little of their existence. — L. P. Harvey, Muslims in Spain, 1500 to 1614, 707

Categorization

• SEED: An essay angle: the counterfactual of Sufi craft guilds as underground survival infrastructure in Iberia — why the mechanism that worked in Tunis never emerged in Spain.