Like the lace kniting pattern on top, and precisely *that* is the one without a legend for symbols - I think the "U" is a yarn over or yo, and the downward arrow is a ~~ УЗОРЫ ДЛЯ ВЯЗАНИЯ.
Posts on the topic of 05 - Ажур. added by Nadezda Vasiljeva
Lace and cables chart
Set loop from classic to unusual.