Think of a random person on the street or bus. They have a reasonable expectation that there is a fare, that it is noted somewhere and an expectation that the driver knows it or has the leaflet. They also have a rough expectation of where on the bus stop the times are when the bus drives and where the bus stops (or were reasonable enough to ask the driver if they stop where they want to go). In general, they know their way around and are law abiding.
Now, this person is on the Bus, and we grab them to ask "Is this demand for the shape the attribution shall take reasonable?" They are pretty much a stand in for the theoretical perfect juror - or rather "finder of fact", where there is no jury (e.g. bench trial or civil law jurisdictions as opposed to common law ones). While this test isn't explicitly existing there, very similar ones exist in civil law.
Since the reasonable person is law abiding, an attribution to a person's alias that would be illegal is not reasonable (e.g. you can not use "Heil Hitler" as attribution line in Germany, as that wuld be considered illegal in many countries in many regards).
Determining what is reasonable
What is reasonable is a question to the Fact finder, who needs to put themselves in the shoes of the ordinary person on the bus.