For short identifiers, I think you missed an important detail.
> Also related: (in particular local) identifiers and names should be short.
The general idea is that the more distant the identifier is, the more descriptive is should be. Because you don't have as much context, and it is also a hint: if you see a long, descriptive name, it is more likely to be global.
And descriptive doesn't mean long. You still need to try making your descriptive names as short as possible. For example "timeSinceMidnightInSeconds" can be shortened to "secondsSinceMidnight" without loss of information: seconds are a unit of time, no need to repeat it.
> Also related: (in particular local) identifiers and names should be short.
The general idea is that the more distant the identifier is, the more descriptive is should be. Because you don't have as much context, and it is also a hint: if you see a long, descriptive name, it is more likely to be global.
And descriptive doesn't mean long. You still need to try making your descriptive names as short as possible. For example "timeSinceMidnightInSeconds" can be shortened to "secondsSinceMidnight" without loss of information: seconds are a unit of time, no need to repeat it.