I found this link:
Annual Increases - The Pensions Advisory Service (TPAS)
Increases are sometimes limited to a maximum amount. Capping an increase in this way is known as Limited Price Indexation (LPI). This is common in private sector schemes, whereas increases in public sector schemes tend not to be capped.
I also found this link:
http://www.mod.uk/NR/rdonlyres/73C97..._explained.pdf
But the file is scrambled.