Boot facilities are used to indicate dependencies in init scripts, as defined in a previous section. Facility names that begin with a dollar sign ('$') are system facility names, defined by the LSB, and MUST be provided by distributions.  LSB applications must not provide facilities that begin with a dollar sign. This document defines the following facility names:
|$local_fs||all local filesystems are mounted|
|$network||low level networking (ethernet card; may imply PCMCIA running)|
|$named||daemons which may provide hostname resolution (if present) are running|
|$portmap||daemons providing SunRPC/ONCRPC portmapping service (if present) are running|
|$remote_fs||all remote filesystems are mounted.|
|$syslog||system logger is operational|
|$time||the system time has been set |
Other (non-system) facilities may be defined by other LSB applications. These facilities shall be named using the same conventions defined for naming init.d script names. Commonly, the facility provided by an LSB application init.d script will have the same name as the name assigned to the init.d script.
The dollar sign does not indicate variable expansion as in many Linux utilities. Starting a facility name with a dollar sign is merely a way of dividing the namespace between the system and applications.
as defined in RFC 1833
In some LSB run-time environments, filesystems such as /usr may be remote. Many applications that require $local_fs will probably require also require $remote_fs
i.e., using a network-based time program such as ntp or rdate, or via the hardware Real Time Clock