W3 validations pipe('|') symbol is not allowed for URL's

Hi,

We are displaying multiple event categories on front-end, and the url to Events displaying as: "&catids=47|48|49|50|51|54|53|55|56"
But pipe('|') symbol is not allowed for URL's pew W3 validation. Can we fix it somehow?
https://validator.w3.org/nu/?doc=http%3A%2F%2Ffcgma.devsoho.com%2F

Please advise,
Sandra