When is a strike not a strike? The answer may be when no one notices your absence.
After recent industrial action by the University and College Union, a union representative at the University of Nottingham wrote to members urging them to register their absence with managers in case they had not been missed.
In an email published by the student magazine Impact, Mike Byrne, branch secretary of the UCU, says: "In our sector the point of a one-day strike is largely missed if institutions do not get a clear indication from everyone who participated...The fact is that in many cases our absence may not have been noticed!"
Dr Byrne told Times Higher Education that he was making the point that on any given day only a minority of lecturers had classes timetabled.
"While cancelled classes are a very visible sign of industrial action, strike action taken by colleagues who are not teaching on that day is far less visible," he said.
"These staff will be working on research or administrative duties, and the nature of these duties is such that their presence or absence on a given day will often not be noticed."
He added that there was "a very good level of support from members who attended picket lines" on the days of the strike action at Nottingham on 22 and 24 March.
Similar strikes have been held at other universities, over job security, pay and pensions.
However, the efficacy of one-day strikes has been questioned by some THE readers.
Writing in an online comment thread, one calls for more sustained action: "One-day strikes achieve very little. A national open-ended walk out and refusal to mark final papers is what is needed to concentrate the minds of management and government."
But others questioned whether this would have the desired effect.
"I don't think there's much support or sympathy for academics, out amongst the public," a second reader writes. "The reality is that everyone across the public and private sector is feeling the pinch, and academics have to take a hit like everyone else is doing."