[VOUnit] How to express the unit of a dimensionless quantity?

[alberto micol]

The latest version of the VOUnits/20231215/REC-VOUnits-1.1 document 
states that:
1.- In §2.2: empty strings are invalid
2.- In §2.2: the string ‘1’ indicated a dimensionless quantity
3.- In §2.8: data providers should use an empty string for unitless quantities
(excerpts from the standard are shown below)

3. clearly contradicts 1. and 2. May I kindly ask for an errata? 

Given the above, what shall I use for the units of the following unitless/dimensionless quantities:
- spectral resolving power (lambda/delta_lambda)
- SNR
- NCOMBINE (number of exposures co-added in a stacked image)
?

Many thanks,
Alberto

2  The VOUnits syntax (normative) <>
2.2  Parsing unit strings - overview <>[…]
The VOUnits syntax, though it also deems the empty string to be invalid, recognises the string 1 as positively indicating a dimensionless quantity.


2.8  Other symbols, and other remarks <>

[…] <>
If there is no unit associated with a quantity (for example a quantity that is a character string, or unitless), data providers should indicate this with an empty string rather than blanks or dashes. <>
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