PP, do you have a *UK issued* JAR-FCL compliant PPL?
This is taken straight from the ANO, which is the law governing anything that has to do with UK-issued PPLs:
SCHEDULE 7 Articles 64 to 71 and 78
Flight crew of aircraft – licences, ratings, qualifications and maintenance
of licence privileges
PART A
Flight crew licences
SECTION 1
United Kingdom Licences
SUB-SECTION 1
Aeroplane pilots
Private Pilot’s Licence (Aeroplanes)
Minimum age – 17 years
No maximum period of validity
Privileges:
(1) Subject to paragraph (2), the holder of a Private Pilot’s Licence (Aeroplanes) is entitled to fly as pilot in command or co-pilot of an aeroplane of any of the types or classes specified or otherwise falling within an aircraft rating included in the licence.
(2) The holder may not—
[...]
(c) unless the licence includes an instrument rating (aeroplane) or an instrument meteorological conditions rating (aeroplanes), fly as pilot in command of such an aeroplane—
(i) on a flight outside controlled airspace if the flight visibility is less than three km;
(ii) on a special VFR flight in a control zone in a flight visibility of less than 10 km except on a route or in an aerodrome traffic zone notified for the purpose of this subparagraph; or
(iii) out of sight of the surface;
[...]
(e) unless the licence includes an instrument rating (aeroplane), fly as pilot in command or co-pilot of such an aeroplane flying in Class A, B or C airspace in circumstances which require compliance with the Instrument Flight Rules;
(f) unless the licence includes an instrument rating (aeroplane) or an instrument meteorological conditions rating (aeroplanes), fly as pilot in command or co-pilot of such an aeroplane flying in Class D or E airspace in circumstances which require compliance with the Instrument Flight Rules; or
[...]
These are restrictions on the *license*. They apply worldwide unless the applicable condition (IR or IMC) is met. So the holder of a UK-issued (JAR-FCL or national) PPL may not fly out of sight of the surface UNLESS he holds an IMC or IR. Period. And yes, this is not entirely according to JAR-FCL. So this *license* restriction is lifted (or replaced by something else) if you trade in your UK-issued license for another countries license.
Now IF said PPL holder also holds the IMC or IR, the *license restriction* is lifted. But there may still be *airspace restrictions* or other restrictions in place that required him from flying out of sight of the surface. These restrictions may be buried in the VMC minima that are defined for the various classes of airspace (A-G) or elsewhere. That's what bookworks quote is about.
(Edited: The ANO section quoted is about old-style UK licenses. But the section on JAR-FCL licenses is essentially the same and has the same restrictions.)