What XML is
XML marks up data with nested named tags and optional attributes. It is verbose, strict about being well-formed, and can carry a schema that says what shape a document must have.
Enterprise integrations, government data feeds, RSS, SOAP services and older document formats.
What Textile is
Textile marks header cells with |_. and data cells with plain pipes.
Redmine, and older Rails applications.
What changes when you convert XML to Textile
The first repeating element is treated as the rows. Attributes are read alongside child elements and prefixed so they do not collide with a same-named tag. Nesting one level deep becomes dotted column names; deeper structures are kept as text.
The header row is written with the |_. marker so it renders as a header.
What carries over from XML to Textile
XML records 3 things about a table that Textile has no way to hold.
An empty cell and a missing one are the same thing in Textile, so a null and an empty string in the XML both come out blank and can no longer be told apart.
XML can hold a value that is itself a list or an object. Textile has only flat cells, so nested values are flattened into one cell rather than being spread across columns.
A line break inside a cell ends the row in Textile, so line breaks are replaced rather than carried through.
Textile marks header cells differently from data cells, so the keys are lifted out and written once as a marked header row rather than repeated on every row.
The identifier 007 comes out of the Textile as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.
The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a Textile file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the Textile.