"Understand that detailed functional requirements could be documented in various ways, e.g. in textual form but also in many graphical forms that usually add more precision, less interpretability, but a sometimes harder to create and understand compared to plain language requirements"
The last part of the sentence sounds somewhat strange and even seems to be a little contradictory (how can the be less interpretable if they are hard to understand?). I would suggest to rather write"but - depending on what notation is used - may require more expert knowledge to create and understand them than plain text requirements."
"Understand that detailed functional requirements could be documented in various ways, e.g. in textual form but also in many graphical forms that usually add more precision, less interpretability, but a sometimes harder to create and understand compared to plain language requirements"
The last part of the sentence sounds somewhat strange and even seems to be a little contradictory (how can the be less interpretable if they are hard to understand?). I would suggest to rather write"but - depending on what notation is used - may require more expert knowledge to create and understand them than plain text requirements."