Is there a industry standard for PDF Map alt text for screen readers?

[Amanda__Huber]

Hi There, 

Our team has been working on standardizing the Alt text across all our PDF Maps and we're curious if anyone knows if there's an industry standard out there for best practices for what to describe for a map?

We've found a few resources for alt text recommendations for complex images and we're aware of best practices for image alt text but so far nothing for describing appearance of maps specifically.

Is there a best practice for how detailed or lengthy our alt text descriptions should be? For example, should we be describing wayfinding instructions for accessing the parks (which maps inherently show) or the ecosystem/landscape of the park, what about amenities within? 

We have a few examples but we're just not sure what the industry standards are or if industry standards for park maps even exist, so we thought we'd reach out here. 

Thanks in advance for any insight anyone can bring to this!

Best, 

Amanda Huber