Clyde said:

>signs, and nothing on the positive lead. I have no idea why the convention
>changed, but it did.

  I noticed that, too. Seems like it wasn't that long ago;
  a decade or so. Somebody, somewhere must know the reason for the
  change. Any capacitor industry insiders on this list?

>
>Axial lead electros also used to have (still do AFAIK) an indented ring
>at the positive end, but that doesn't help much with single ended ones :-)

  On aluminum electrolytics, the crimp holds the seal in place.
  It's not explicitly for indicating polarity, but the can is the
  negative terminal so for axial caps the open end where the
  positive lead emerges is always the crimped end. For radial caps
  the can may not be part of the circuit at all; I don't know why
  this is.

  Reg Neale