The categories represent different status in University terms and, whilst not prescriptive, the following guide may be helpful:
The title Honorary Professor is appropriate for someone worthy of a Chair position at the University or the equivalent, ie. someone very eminent in their field. Nominations for serving academics from other universities (whether in the UK or abroad) may normally be considered only if they hold professorial positions within those institutions. Two references external to the University are required when submitting a nomination. Schools are responsible for taking up references and ensuring that the referees are of suitable seniority whether inside or outside academia.
The recommendation for an appointment should include a note of the role or status of each referee. It is advisable to have one of the referees independent of the current employer of the person being nominated. In addition existing Honorary Professors should not be asked to provide references as this would not be considered to be external to the University for this purpose.
The title Honorary Fellow equates broadly to the Honorary Professor title and is to be used where a senior and eminent appointment is proposed but where it is not appropriate to award the individual concerned an academic title. It is equivalent in status to the Honorary Professor title but it is more appropriate for someone with an industrial/entrepreneurial background.
As with Honorary Professor appointments two references external to the University are required when submitting a nomination and Schools are responsible for taking up references and ensuring that the referees are of suitable seniority whether inside or outside academia. The recommendation for an appointment should include a note of the role or status of each referee.
At least one of the referees should be independent of the current employer of the person being nominated. In addition existing Honorary Professors or Fellows should not be asked to provide references.
The title Honorary Associate Professor should only be conferred on those who would be deemed appropriate for an Associate Professor appointment within the University.
Honorary Assistant Professor status applies to the majority of appointments made.
UK Heads of School are sent details of the scheme in February each year asking for any Honorary Professor or Honorary Fellow recommendations. These will be considered by a Pro-Vice-Chancellor