xsd:string is a good catch-all type for these extra fields.

string 是这些额外字段的良好的全捕获（catch-all）类型。

youdao

Once you have a root name established, add on extra fields to specify vocabulary names and version numbers.

在建立了根名称之后，添加额外的字段来指定词汇表名称和版本号。

youdao

The termio structure has some extra fields in Linux with which you can mention the input and output speeds.

Linux中的termio结构多了几个域，您可以使用它们来设置输入和输出速度。

youdao

Enhanced oil recovery (EOR) technologies get extra petroleum out of depleted fields by squeezing CO2 into them.

ECONOMIST: Combating climate change

To improve the efficiency of this process, he worked out a way of arranging permanent magnets so as to concentrate their combined fields in a single direction, providing extra oomph.

ECONOMIST: Maglev trains

Father-of-three Steve Lukacs, a governor at one of the schools in Tunbridge Wells facing expansion, said adding extra classrooms put pressure on existing school halls, canteens and playing fields.

BBC: Kent parents fight school expansions