This ugly and unnecessary symbol is only fit for forms and lists and specifications and things of that sort; it should find no place in any document that has any pretence to literary form. It can always be dispensed with. Instead of writing (say) "soldiers and/or sailors" we can write "soldiers or sailors or both". Moreover, whatever claim may be made on behalf of and/or as a saver of space and time, there can be no possible justification for using it where or by itself is enough, as it is in:
Professional fees should be included when paid to any architect, surveyor or engineer acting as such in an advisory and/or supervisory capacity.