So we left handed people who knit mirror (left to right) have to make small adjustments to the meaning of stitches that lean a particular way. Right handed people read a chart right to left and knit right to left which means they are approaching their stitches from the right. Mirror knitters knit left to right and we read charts left to right which means we approach our stitches form the left.
In regular charts where decreases are marked we just switch the meanings. So in a standard chart / = k2tog. And of course a k2 tog is going to slant to the right if you are approaching the stitches from the right. But for mirror knitters \ = k2tog because we are approaching the stitches from the left.
At 1st when you are new to charts and knitting it helps to make these notes on your chart. But as you get comfortable with it you will find you no longer look at the legend and simply do what the stitch is telling you to do because you have come to know how to make things lean left or right and the symbole will either lean left or right \ or /.
The same goes for cables. Because mirror knitters approach the stitches from the left, knitting left to right, our terms for cable symbols also need to be switched.
Your standard, simple cable is a front cable where you place your stitches onto a cable needle and hold them to the front. In mirror knitting this results in a right leaning cable (it leans in the direction you knit). But a right handed knitters front cable will lean to the left because they are knitting right to left.
So when the chart shows a left leaning cable and tells you it means C#F you will C#B and hold your stitches to the back. Or if it shows you a right leaning cable but tells you to c#b you will need to c#f to accomplish the same symbol in the chart.
Again, as with any chart, when you are new it can help to make the notes for the stitches YOU have to do to create the symbol in the chart. But as you get used to charts, cables and knitting you won't need to make these notes as it will be second nature to create the cable the leans proper to the chart instructions. But until then, here is a sample and/or suggestion as to the notes you may want to make on your own chart before embarking on the project.
Here is the chart legend for Knotty but Nice hat (which is a free pattern) with the changes a mirror knitter will have to make.
You will follow the directions for the new meanings for the symbols on the right.
In written patterns it's not usually a big deal but your c4b will lean the opposite way as the designer intends. this may affect a few patterns that are dependent on cables coming together in a particular way. But in general a written pattern can just be followed as written. IF you find you are having problems, all you need to do is swap the front and back instructions.
Life would be much easier if designers simply referred to cables as left and right leaning. No translation needed if they did that ♥