Conventions for writing down uncertain relationships

Alberto Guido Chester

Hi all
I use My Heritage software.
Is there any broadly accepted convention in this or other software to write down a relative I am not sure of ?
Many years ago, I used to keep those not sure relations in my papers. 
But now, when online trees will be available for distant relatives even when I am not living any more, I feel these cases should be included in the tree.
I think of noting something like "relation not proven yet" besides the name, but feels untidy to me.
A dotted line (like before printed trees existed) would be appropriate, but I do not think they are available in genealogy software.
All ideas are welcome.
Thanks in advance

Alberto Guido Chester
Buenos Aires, Argentina