Foul Play? Capitals and Abbreviations

You’ve probably seen plenty of clues along the lines of

Confusion by river wharf (4)

for PIER [PIE + R], and most likely not thought very much about them. But could there be an issue here? Chambers lists the abbreviation R for ‘River’ but not for ‘river’ without an initial capital. For a good reason, too – the only place the abbreviation is seen (to our knowledge, anyway) is on maps, where ‘R. Thames’, for instance, is a shortened form of ‘River Thames’. And how about

Lively fight with master (4)

for WARM [WAR + M]? Again, Chambers shows M as an abbreviation only for the capitalized form, ‘Master’, because ‘M’ here is in reality only a component of multi-letter abbreviations, eg MA for ‘Master of Arts’ (so even ‘Master’ for M may be an issue, which will be the subject of another discussion).

For many abbreviations there is no problem – they will be capitalized in their expanded form and when used in wordplay (eg ‘A/American’), or non-capitalized in both (eg d/diamonds, k/king). And of course if the expanded form of the word appears at the start of the clue then all is well, eg

Street with place for vehicles awaiting hire (5)

for STAND [ST + AND], since ‘Street’ with the capital is absolutely fine for ST.

What is the referee’s verdict? Your views may prompt a reassessment, but the initial judgement is a yellow card – it’s not serious foul play, in that the practice is not unfair to the solver, but neither is it entirely sound.