Unicode answer is not so great because you can express compiled program in Unicode which obvious is non-text. Math expressions are always text because they always fit TeX or LaTeX.
Architecture is a beautiful example which provokes thinking. From first view it is a non-text, but an architect Antoni Gaudà has developed an attitude with hanging models which made his architecture plans to share some abilities of text even not being written. You may tell me I am crazy but his hanging models is a WYSIWYG model of something from real world so I consider it a text despite it could not be simply copied. IDK maybe a modern architect software shares that attitude, for make these models be copied easy. So my opinion is that architecture plan may be text at least from a structure point of view.
Architecture is a beautiful example which provokes thinking. From first view it is a non-text, but an architect Antoni Gaudà has developed an attitude with hanging models which made his architecture plans to share some abilities of text even not being written. You may tell me I am crazy but his hanging models is a WYSIWYG model of something from real world so I consider it a text despite it could not be simply copied. IDK maybe a modern architect software shares that attitude, for make these models be copied easy. So my opinion is that architecture plan may be text at least from a structure point of view.