Terminology, units and numbers on screen
Coded vocabularies exist so that systems can agree about what a thing is. They were not designed to be read aloud on a screen, and the gap between a code's canonical form and its readable form is a design responsibility that often goes unclaimed.
A code is not a label
Standard vocabularies are maintained by standards organisations for the purpose of unambiguous exchange between systems. Their preferred terms are precise, long, and frequently written in an order that suits sorting rather than reading. Displaying them verbatim is faithful and often unhelpful.
The alternative is not to invent a friendlier vocabulary. It is to treat display as a distinct layer: keep the code as the identity, choose a display term that a reader will recognise, and make the canonical form retrievable for anyone who needs it. Sites that conflate the two end up either unreadable or unexchangeable.
Abbreviation is compression with a lossy step
Abbreviations save space on screens that badly need it, and they are locally learned. The same short string can mean different things in different departments, and a display that inherits one department's habit and shows it to everyone has quietly introduced ambiguity that did not exist in the underlying data.
Where an abbreviation must be used, the expansion should be reachable without leaving the screen, and it should not depend on hover alone, which is unavailable on touch and invisible to keyboard users.
Units and the bare number
The most common serious display defect is a value shown without its unit, on the assumption that the reader knows which unit the system uses. That assumption holds until data arrives from somewhere with a different convention, at which point the number is still rendered, still looks authoritative, and now means something else.
Units should travel with values through every layer of the interface, including summaries, tooltips, exported tables and printed views, which are the places they are most often dropped. Where a system converts between unit systems, the conversion should be visible rather than silent, because a reader who cannot see that a conversion happened cannot check it.
Numeric legibility
Numbers meant to be compared should be right-aligned in a tabular font so that digits line up by place value, which lets the eye compare magnitude without reading. Decimal places should be consistent within a column and should reflect the precision of the measurement rather than the precision of the arithmetic that produced it. A value rendered to six decimal places asserts a confidence the measurement does not have.
Thousands separators help at four digits and above. Leading decimal points without a zero are a genuine hazard on a screen that may be viewed at a distance, at an angle, or through a smudge, and the zero costs one character.
Context is part of the value
A value shown alone is a value the reader must interpret from memory. Showing the reference interval, the units, the time it was taken and the previous value converts a lookup into a reading task, and reading tasks are far more reliable than recall tasks.
This is the general principle behind most of what works in this area: put the information needed to interpret a thing next to the thing, at the size it needs to be read, rather than one navigation step away in a place the reader must know to look.