This Recommendation: ?C provides engineering solutions for lightning protection and safety for small-size telecommunication installations under poor earthing conditions. These protection measures are not common requirements for all kinds of circumstances and have defined conditions for application respectively. If these installations have equivalent inherent capacity and function@ the same results can be acquired. ?C is not intended to replace traditional rules on bonding configurations and earthing. These protection measures are compromised alternatives under poor earthing conditions due to the restriction of circumstance or expense. ?C is intended to apply for the installations powered by a.c. mains and comply with [IEC 60364 series] or national standardizing bodies on a.c. power installations. ?C is also intended to apply for the installations powered by remote powering output at up to 400V d.c. IT system and comply with [ETSI EN 302099] and [ETSI EN 301 605]. The applied objects in this Recommendation are the small-size telecommunication installations which are owned by the network operators and under controlled by skilled or instructed persons.