I think it only comes an issue if your, lets not beat about the bushes here > overweight otherwise it really doesnt matter and guys make such as big deal over it claiiming BPenis EnlargementL is fake blah blah blah and yet most if not all medical studies with dicks mesured use BPenis EnlargementL or BPFSL as the core method. Yes the ruler needs to hit the PUBIC BONE and that can be from the side (either) or the top but usually guys do it from the top but in my experience if you hit the BONE correctly from either angle it comes to the same BPenis EnlargementL and yet many feel the side shot is fake because guys have used it in the past not knowing how to measure I guess, pushing the ruler into the actual fatty musculer tissue of the lower abdomen which then becomes not accurate.
I'll actually say this. The most accurate best way to always track your length gains is to use BPFSL - Bone pressed flaccid stretched length - and do this always in the same positon into the pubic bone and not the side oneday, the top the following month. Always do it the same way as before, so if you stood up then always adopt that same position otherwise if you sit nextime the chance is the measurement can change. Sitting and standing measurements do vary.
This method also is great because you need no arousal to become erect, just grip underneath the glans either pull the foreskin back and grip or with the skin covering and pull as hard as you can. Hold for 10-30 seconds and relax, maybe do some kegels and reverse kegels. Then take the measurement. You can even do it for your own diary pulling the cock up 12 O'Clock, down 6 O'Clock and to the 9 & 3 O'clock positions which in time can aid you in homming in on certain areas or just for curiosity sake. Really, Penis Enlargement measurements can be very complex if you want to make them just like bodybuilders measuring body parts can do it cold, after workout and flexed etc etc you decide on how much detail you need but for the same of the mass'ess the stat always usaully noted for erect length is BPenis EnlargementL but BPFSL is an indicator of future length.