Question about the depiction of our solar system on the Pioneer Plaque

The Pioneer plaque(s) have the image of the solar system on them. Along with that is the relative distances in binary, right? What exactly do these mean? Like above mercury is says I-I- how does one read that? also says the unit is 1/10 of Mercury's orbit is the unit?
Please explain this to me.

The I means 1 and the - means 0
Decimal numbers have digits from 0 to 9 and each place is 10 times the one to it's right.
For example the number 123 is 1*100 + 2*10 + 3*1
Binary numbers have bits (binary digits) from 0 and 1, with each position being twice the one to it's right.
So 1-1- is binary 1010
Binary 1010 is 1*8+0*4+1*2+0*1=10 in decimal (base 10), so Mercury is 10 times 1/10 of the distance of Mercury, in other words 1 times the distance of Mercury.
Earth's distance from the Sun is II-I- which is 11010 binary which is
1*16+1*8+0*4+1*2+0*1=26/10 or 2.6 times the distance of Mercury.

First let me explain how binary numbers are written, in case you don't already know. Left to right, the digits represent 1, 2, 4, 8, 16, 32, and so on (the value of each digit is double the one to its right). So the decimal numbers convert as follows:
1 = (1) = 1
2 = (2 + 0) = 10
3 = (2 +1) = 11
4 = (4 + 0 + 0) = 100
5 = (4 + 0 + 1) = 101
6 = (4 + 2 + 0) = 110
7 = (4 + 2 + 1) = 111
8 = (8 + 0 + 0 + 0) = 1000
9 = (8 + 0 + 0 + 1) = 1001
10 = (8 + 0 + 2 + 0) = 1010

If the unit is 1/10 of Mercury's orbit, then Mercury's orbit should be at a distance of 10 units from the sun. That's what the I-I- represents. It's another way of writing 1010 (the bar used as 1 and the hyphen used as 0), which as we as seen above is 10 in decimal numbers.

Mercury is at a distance of 1010 (=10 units),
Venus is at 10011 (=19),
Earth is at 11010 (= 26),
...and so on.

actually the plaque shows the sun in relation to a dozen or so pulsars.