Help with chart-reading?

[jackandahat]

I suspect this is going to be one of those where the answer is so obvious I'll kick myself, but I've looked and looked and I can't work it out.

I'm trying to learn to read charts, and I want to make this jumper. So I'm writing out the charts and swatching and I've done just fine up until I hit row 15 or chart 3.

There's 2 symbol there I can't understand. One looks like C3FP but all-white, instead of white with a grey box. C3F is all-white, but doesn't have the extra little lines. The other, likewise, but C3BP/C3B.

I've asked elsewhere and been told "Just look at the key", but I don't see it on the key - so I'm feeling pretty stupid here, can anyone help?

Edit: It's been suggested that the designer just copied rows 1-14 and turned them all white, rather than editing the symbols, and that I should just C3F/C3B, no purling. Which sounds sensible to me - does this seem plausible?

Comments

[aedifica]

Looking ahead, it looks like whatever it is also happens in rows 5 and 19 of chart 4.

[jackandahat]

Damn, how did I miss that too? Hopefully by the time I get there I'll have a better sense of it - I'm assuming the row 5s should be shaded, the row 19s shouldn't. Thanks for pointing it out.