champagneandroses, I think nappyaddict just means that on previous threads wrt weaning someone always comes along and says 'oh, that's not in the developing world though'.
It is sad that we aren't told the score quite often from Hv's etc, I was told by my HV in 2000 that it should be four months, but not to adjust DD's age(she was 8weeks prem), I didn't listen and age adjusted anyway because my MiL said it was bollocks(she had had three prem children).
When DS was born in 2004, I was told it was now six months, and I waited, I had absolutely no idea why it was six months though.
Only since I joined mumsnet have I done some proper research and found the reasons behind the guidelines. Though now they recommend waiting until six months but muddy the waters by saying absolutely no solid food before 17weeks, which makes people think 17 weeks will be ok, when we have absolutely no way of telling if it is or not.
If you read the DOH weaning leaflet here even that says
"If you decide to wean at any time before six months, there
are some foods that should be avoided as they may cause
allergies or make your baby ill. These include wheat-based
foods and other foods containing gluten (e.g. bread, rusks,
some breakfast cereals), eggs, fish, shellfish, nuts, seeds
and soft and unpasteurised cheeses. Ask your health visitor
for advice, especially if your baby was premature.
Solid foods should never be introduced before four months."
which of course almost advocates weaning before six months! It's ridiculous.
If you look here it explains when/what the guidelines were changed from/to.