I've no idea how accurate this is
I've noticed that Thomas B. Ramsden patterns (Wendy, Peter Pan, Robin, etc.) often use terms that I've been told by experienced knitters are UK specific or "old-fashioned" terms -- "yarn forward" for "yarn over", for instance, on one of my first scarves.
ETA: here's the explanation given, so we have it here:
'Top sewing' in knitting should not be confused with 'top-stitching' in sewing, which means stitches that are used for decorative purposes, such as round collars and openings on coats etc. Top sewing in knitting generally means stitching like a whip stitch over the outer edges of the 2 pieces being joined - this allows you to open the seam out, almost edge to edge afterwards to avoid bulkiness on seams, esp. in baby's items, for better comfort. The stitches need to be a regular length into the seam, and fairly close together.