Ilford intermittent agitation protocol

Did Ilford change its intermittent agitation protocol?

When I started developing my own b&w film, perhaps 15 years ago, I was taught (and I'm sure I read) to invert the tank for the first minute and 10 seconds out of every minute thereafter. I know that Steve Anchell in his book "The Darkroom Cookbook" advocates this protocol. I was researching development times for FP4 (haven't processed any in quite a while) and was surprised to read that Ilford defines intermittent agitation as inverting the tank for the first 10 seconds, not one minute for all its films. The date on the chart is June 2010. Was this always the protocol or did Ilford make a change, perhaps in 2010?

No, I don't think so.
It has been 4 inversions for 10 seconds every minute.
See page 10 of this PDF dated 2003:
http://www.ilfordphoto.com/Webfiles/200629163442455.pdf
And this one from 2004: http://www.ilfordphoto.com/Webfiles/2006210204272065.pdf
The oldest I can see is this one for the PAN films dated 2002: http://www.ciemnia.net/Ilford/Pan100_400.pdf

There are variants to this method.
Foma recommends continuous agitation or inversion for the first 30 seconds and then for 10 sec every minute.
http://www.foma.cz/en/fomapan-200

I can't go back quite 15 years but certainly 12 years ago when I started the Ilford agitation regime was exactly as Ricardo states

pentaxuser

The massive dev chart app for HP5 and Ilfasol 3 says inversions for one minute and then ten seconds each minute.

Adam W said:

The massive dev chart app for HP5 and Ilfasol 3 says inversions for one minute and then ten seconds each minute.

Click to expand...

The MDC is a compilation of users input. It isn't the manufacturers recommendations.
Always follow the manufacturer as a starting point, then you can go to MDC and deviate from it.
What works for some, might not work for others.

With inversion you need to leave space for the liquid to move.

With a Agfa daylight tank you need to not overfill or they leak.

If you bang and crack a plastic tank they leak.

Apart from an inversion at beginning I don't agitate cept with Agfa tank. I do agitate for stop and fix.

The oldest Ilford datasheet I have here is for FP4 without Plus, so it should be earlier than 1990,
the agitation described there is also 10 seconds for the first minute and than 4 inversions in 10 seconds at start of every minute