Unfortunately there is not real nomenclature. And sometime the same word could be interpreted differently according which book you studied (computer graphic, TV brodcasting, digital video format, photo).
First: RGB is not a colour space but a colour model, so it give just an idea on how colour are made, but it give nothing precise.
When using RGB, usually we intend linear RGB or gamma corrected (R'G'B'). Linear indicates the intensity of light, gamma corrected more how we perceive colours. so an half gray (which seems half way between white and black) is around 18% in linear RGB, or 50% in gamma corrected space
Then we have colour space, like sRGB. In a colour space we define chromacities (of R, G, and B) and the chromacity of white. [Usually the chromacities are given as x,y of CIExyz]. Rec.709 (HDTV) has the same chromacities of R, G, and B, but a different gamma, and a different white.
Often a colour space defines various characteristics. sRGB defines values from 0 to 255 (originally), so a byte, always gamma corrected. Previously it was common to have 100 or 1.0 as values for white (a triplet of such values). Note: values above 1.0 or 100 could be valid. On old analogue TV we can have such values (limited on part of screen and for limited frames, but still allowed).
On digital world signals (e.g. in HDMI), we have full-range RGB: 0 to 255 or limited-range RGB 16-235.
I do not know a good nomenclature, but usually it is obvious. In general: linear RGB has (0.0, 0.0, 0.0) for black, and (1.0, 1.0, 1.0) as floating point number (half or single precision). Floating point number are already a sort of exponential representation, like gamma corrected, and linear: adding light is just an addition (and it doesn't give unwanted cast of colours).
On non-linear colour spaces [gamma corrected] we tend to use integers, often 0 to 255 (or 0 to 1023 in 10 bit) (colour depth, sometime it is given total, sometime as bit per channel). So if you have a colour depth, you are working with integers, so values 0 to 2**channel_depth-1.
It is always good to specify the values, also because there is lack of nomenclature and so often confusion. You see many problems about people not realizing about full-scale/limited-scale images on HDMI signals.
My take: you define "8bit sRGB" (or 24bit): 0 to 255, analog for 10bit, etc. "linear RGB" (or anything with floating point constant, or seeing also R'G'B' in the text): 0 to 1.0. If you see also YCC somewhere, start worrying, because you never know if you have full-range or limited-range. The 0 to 100 is found on text books (especially old), but in that case I prefer to add a % sign, so giving the value automatically from 0 to 1.0.
But like file formats, somewhere you should describe fully your colour space: chromacities (e.g. by referring to sRGB DCI-P3, Apple P3, AdobeRGB, etc,), which gamma correction do you use (there are various functions, Apple on old hardware used different one), and I would write black: 0,0,0, white 1.0,1.0,1.0 (e.v. with range, e.g. negative numbers [for colour "out of gamut", or values ultraluminous), and precision (16bit [half precision] 32 bit [single precision], per channel, or classic 8bit, 10bit, 12bit in case of integers). You need only once, but better to be explicit, especially considering that people in different fields have different expectations.
RGB is a color space, in which colors are defined as proportions of it's components, so RGB colors are 3 values from 0 to 1. True color is sometimes referred to as RGB, but it's not technically correct, since it's combination of color space (RGB), and color depth (3*8 bits).
RGB 0-1 is fine, but RGB digital is more fitting for 0-255 range in my opinion and RGB unreal is really ill-named since it uses real numbers instead of integers for color representations.
With 0 and 1 as RGB values you get these combinations:
000
001
010
100
110
101
011
111
Eight different colors: Black, then blue, green, red, then yellow, magenta, cyan, then white.
(In the order that I listed the rgb color bits in my list)
If you double with a bold attribute, you get the 16 official Linux colors. And I guess that colorspace existed before: it is what you get when you start with 3 "base" colors and mix them to get 6.
A bit number magic also: 2^3=2*3+1+1
8 minus black minus white is 6 colors, in two groups.
