I'm getting an initial impression that there might be three basic forms of
traditional yagi (not log-periodic) when considering the issue of
bandwidth.

Common Yagi (whatever that may be) . This has a fairly narrow bandwidth,
not sure of the typical bandwidth in precentage terms of the designed
frequency. Perhaps 1% at a guess. Here there has been no effort to
concentrate on making any form of wideband antenna.

Optimised Wideband Antenna (OWA). This has a fairly wide bandwidth, not sure
of the typical bandwith maybe 3 or 4 percent of the design frequency. Here
some effort has been put into making something of a wideband antenna, but
the design is not as wideband as is possible.

Wideband Yagi. This is typically the antenna having the widest bandwith.
Not sure of the typical bandwidth, but perhaps about 7% of the design
frequency.

If you were to draw up a list of traditional yagi' designs (including call
letters of the designer if there is one) and place them in order of
increasing bandwidth, what kind of list would you get?

Here is my measly effort:

Yagi (under no classification but yagi)
OWA
Wideband Yagi.

I'm not sure where in a list you put DL6WU, W4RNL, DJ9BV, + other designs I
know not of. Does a DL6WU yagi come under OWA or wideband yagi? Has anyone
drawn up a definitive classification?