Prosemirror-markdown serializer precedence

When creating a new MarkdownSerializer (basing it off the default), how is precedence decided when text has multiple formats? For instance, I added a strikethrough mark into the basic schema and in the serializer, I put

strikethrough: {open: "~~", close: "~~", mixable: true, expelEnclosingWhitespace: true}

Is there any option indicating precedence?

Precedence in what context? The way marks are nested in the output defaults to the order of the marks in the schema definition. mixable will allow the serializer to reorder the mark in relation to other mixable marks to save on closing/opening tokens.

Sorry for the lack of clarification, but the nesting was what I was asking about. Thank you!