possibily it means,

let say
1) Tablespace DATA_ONLY_TBSP has tables only, ( this has no problem to duplicate)
2) Tablespace INDEX_ONLY_TBSP has only indexes of somes tables residing on other tablespace which are not being duplicated , then this is not qualified.
3) Tablespace INDEX_DATA_TBSP has indexes and tables residing on the same tablespace, then this has no problem.
4) Tablespace PART_A_TBSP , this has one of the partitions of a table which is not being duplicated, this cannot be duplicated.

I guess these concepts are closely matching with Transportable tablespaces feature.

Jr