可选、必需和排除（optional, mandatory, and excluded）

Sometimes AND and OR are not enough. If you want to find documents that must contain the term “car”, score those with the term “red” higher, but do not match those just containing “red”.
有时AND和OR是不够的。例如要查找必须包含术语“car”的文档，如果有包含术语“red”更好，但“red”不是必须的时候。

The following example finds documents that contain the term “car”, score those with the term “red” higher, but does not match those just containing “red”:
以下示例查找必须包含术语“car”的文档，如果有包含术语“red”更好，但“red”不是必须：

+car |red

At least one element of a query must match (or not match) for there to be any results.
查询中至少有一个元素必须匹配（或不匹配）才能有任何结果。

All AND and OR constructs can be expressed with these operators.
所有AND和OR结构都可以用这些运算符。