Interesting to read the last couple of replies and in answer: I tried the NIEIEC pocket notes but to be honest, by the time I'd collected the useful info I wanted to carry around with me, I found them just as bulky and un-user friendly as the OSG. And to answer, what's the point - I like to carry around a bit of info in the end pocket of my toolbox and this has proved useful twice just this week. While working at a customer's house (that was up to date with a Schedule of Test Results!) the customer wanted to change 16 ELV down lighters for LEDs. I know, like most will that the Zs should be less than 6.14 but for the LEDs I'd need a C-rated breaker. The choice was back to the van for a fumble through the OSG and a calculator to work out the 80% figure or just read it from the new book I'd bought that was in the toolbox? Same customer wanted to know why I wouldn't fit her 'bathroom' light she'd bought from a DIY store over her shower. I could show her the zone chart in the Electrician's Notes and she was happy. The booklet won't be everyone's cup of tea but having tried it, I'm quite a fan.