Scott Hansen offers the following from David Whitehouse’s dictionary of glass terms. (David Whitehouse is executive director of Corning Museum of Glass).
The CMoG Glass Dictionary compiled by David Whitehouse defines threading as follows: The process of winding a thin trail of glass around an object to create the appearance of parallel lines. In 1876, W. J. Hodgetts of Stourbridge, England patented a machine that produced very regular and closely spaced threads.

The Dictionary does not have a definition of reeding.