Generic profile parameters are used to specify several items, such as ports on which a software component is to receive requests.
<xx> stands for a number between 0 and 9.
If you want to specify multiple ports you can set, for example:
icm/server_port_0 = PROT=HTTP, PORT=8080, TIMEOUT=15
icm/server_port_1 = PROT=SMTP, PORT=80, TIMEOUT=45, EXTBIND=1, HOST=prd.sap.de
icm/server_port_2 = PROT=HTTPS, PORT=443, TIMEOUT=15, PROCTIMEOUT=45, VCLIENT=0