This is a warning about a change of language, especially for professors emeriti.
I received a letter requesting that I give an invited lecture at a certain conference in another country and I agreed. Once upon a time, such an invitation meant that the organisation in question would cover the expenses incurred. Sometimes the arrangement was that the organisation would pay for the expenses, except for travel to the conference.
I found in the present case that no financial aid was offered. So I thought that I should bring this "change of language" to the attention of colleagues.
John Allen, Professor emeritus of engineering science, University College, Oxford