Since a calculated expression can be long, and contain characters illegal for XML tags, calculated columns are named simply by their position.

因为计算过的表达式可能很长，并且可能包含对于XML标记来说非法的字符，所以计算过的列仅由它们的位置命名。

youdao

What Attwell has done is relatively simple: he saw an expression of demand for books in the illegal copying and found a way to facilitate that demand legally.

FORBES: The Future For Bookshops Is To Pave The Cowpaths