Many more comments (documentation) on what key values are supported, where,

and what their default values are (if not present).

ctrl/services.ini

 ; ctrl/services.ini file
 
-; Each section is a service, the [section name] is the service/protocol name
+; Each section is a service, the [section name] is the service/protocol name (by default)
 
-; Supported options (separated with |):
+; $Id$
+
+; Global keys supported (in root section and/or per service section):
+
+; LogLevel (default: LogLevel specified in sbbs.ini)
+; StackSize (Thread stack size, advanced use only, default: 0 - unspecified)
+; MaxClients (default: 0 - unlimited)
+; ListenBacklog (valid for TCP services only, default: 5)
+; Options (default: 0, see below for valid bit flag definitions)
+
+LogLevel=
+StackSize=0
+MaxClients=10
+ListenBacklog=5
+Options=0
+
+; Each service also supports the following keys:
+
+; Enabled (default: true)
+; Command (command-line to execute)
+; Protocol (default: service/section name)
+; Port (TCP/UDP port number or name, default: look-up TCP or UDP port by service/protocol name)
+; Interface (default: network interface IP address specified in sbbs.ini [services])
+; Host (default: unspecified) - only run on the specified hostname
+; NotHost (default: unspecified) - do not run on the specified hostname
+
+; Advanced JavaScript execution keys:
+; JavaScriptMaxBytes
+; JavaScriptContextStack
+; JavaScriptThreadStack
+; JavaScriptBranchLimit
+; JavaScriptGcInterval
+; JavaScriptYieldInterval
+
+; Supported Options bit flags (separated with |):
 ; 	NO_HOST_LOOKUP
 ;	NO_RECYCLE
 ;	MUTE
@@ -15,70 +49,58 @@
 ; Network News Transfer Protocol (NNTP)
 [NNTP]
 Port=119
-MaxClients=10
-Options=0
 Command=nntpservice.js -f
 
 ; Message Send Protocol service
 [MSP]
 Port=18
-MaxClients=10
 Command=mspservice.js
 
 ; Message Send Protocol service (UDP)
 [MSP-UDP]
 Port=18
-MaxClients=10
 Options=UDP
 Command=mspservice.js
 
 ; Active User service
 [ActiveUser]
 Port=11
-MaxClients=10
 Options=NO_HOST_LOOKUP
 Command=activeuserservice.js
 
 ; Active User service
 [ActiveUser-UDP]
 Port=11
-MaxClients=10
 Options=UDP | NO_HOST_LOOKUP
 Command=activeuserservice.js
 
 ; QOTD service
 [QOTD]
 Port=17
-MaxClients=10
 Options=NO_HOST_LOOKUP
 Command=qotdservice.js
 
 ; QOTD service (UDP)
 [QOTD]
 Port=17
-MaxClients=10
 Options=UDP | NO_HOST_LOOKUP
 Command=qotdservice.js
 
 ; Finger Service
 [Finger]
 Port=79
-MaxClients=10
 Options=NO_HOST_LOOKUP
 Command=fingerservice.js
 
 ; Finger Service, fast (for inter-BBS instant-messaging)
 [UDP-Finger]
 Port=79
-MaxClients=10
 Options=UDP | NO_HOST_LOOKUP
 Command=fingerservice.js
 
 ; Archaic HTTP-like protocol
 [Gopher]
 Port=70
-MaxClients=10
-Options=0
 Command=gopherservice.js
 
 ; Internet Relay Chat (IRC) Daemon (Server)