2.2.3 Valid Selection
Many constructs in file types described by this document refer to ranges of CPs. When such ranges specify that they are restricted to a valid selection, the following rules apply.
If the range contains content from more than one table cell at a particular table depth, then it MUST contain only whole table rows at that table depth. For further specification, see Overview of Tables (section 2.4.3).
If the range contains a field begin character, field separator character, or field end character, then it MUST contain the entire field. For further specification, see Plcfld (section 2.8.25).
Both ends of the range MUST be in the same document part.
If the range is in the footnote document, then both ends MUST be in the same footnote. For further specification, see PlcffndTxt (section 2.8.20).
If the range is in the header document, then both ends MUST be in the same header or footer. For further specification, see Plcfhdd (section 2.8.22).
If the range is in the comment document, both ends MUST be in the same comment. For further specification, see PlcfandTxt (section 2.8.8).
If the range is in the endnote document, then both ends MUST be in the same end note. For further specification, see PlcfendTxt (section 2.8.17).
If the range is in the textbox document, then both ends MUST be in the same textbox. For further specification, see PlcftxbxTxt (section 2.8.32).
If the range is in the header textbox document, then both ends MUST be in the same textbox. For further specification, see PlcfHdrtxbxTxt (section 2.8.23).