Integrative Levels Classification project ILC2 schedules developing schedules how it works people references
ILC class sd3s

ILC developing version
Expanded class sd3s

   ▲  broader class

▽ ⌕         sd3s                 handling systems; plumbing  ≈ DDC 690
▽ ⌕         sd3sr                      water supply
▽ ⌕         sd3ss                      sewage
 
Connected classes:
 

specificity 
current: 99 

   
Move to another main class:
a b c d e f g h i j k l m n o p q r s t u v w x y

or

or insert a term and do a new