SLAC 15 Dec 1995
This paper was endorsed by the SLAC WWW Technical Committee, May, 1995.
During the page migration, we have the opportunity to improve long-term maintainability of the files and make them easier for authors (and users) to manipulate than currently on VM. By collecting the files together in a single namespace, long-term system maintenance will be easier than presently (although it may be a bit harder for page maintainers to install files outside their own space, especially at startup when they may have to learn various AFS administrative skills.) The WWW access rules can be simpler, and the URL can reflect the file names in a clear-cut way. Using mnemonically named files where hierarchical and longer names may be chosen than in VM should also make it easier for page authors to find and update their files, and even for page users to remember the URL when they need to reference it explicitly. Following the naming guidelines below is intended to promote a degree of consistency so people, especially page maintainers, can infer, to some degree, where to find files. This consistency should foster a comfortable "look and feel" to using the namespace, both actively and passively.
Having a well-structured namespace is expected to lead to even more benefits in the future. For example, we expect it will help in any migration we undertake to the successor(s) to the URL addressing scheme that will be, developers expect, more robust over time and operating system changes than current URL.
www1are identical except that the filename has an additional prefix of:
which can be abbreviated:
So for the "SLAC Experiment E144 Home Page," the fully qualified URL is:
and the file is:
Production pages and files are generally those linked to from the SLAC
Home Page or those hanging off that. Production pages belong in
production file space,
for easier maintenance of the rules file,
space, performance, and the information architecture itself.
In the case of potentially large collections, there may be a link from
/afs/slac/www space into a group repository.
is a symbolic link to ES&H's group space in:
but the URL for accessing the files looks the same as if they actually resided in production WWW space. For example, here is the URL for the ES&H Home Page:
The global WWW visibility of the files should still be clear because all the
files reside in the
Note that this practice of linking from production to group space should only be used for very large collections of files when putting them in the production Web page space is impractical. Symbolic links connecting globally visible Web space to space that is normally seen only by those logged onto a SLAC host may lead to unpleasant surprises. Generally speaking, it is better practice to link from more restricted (more secure) to less restricted (less secure) space.
For example, you should link
/afs/slac/www/comp/form/acctform.ps. This way, the link clearly
points out of a directory that can usually only be seen by people logged in to
a SLAC host (or, soon also with SLAC-cell AFS privileges)
and into space well-known to be displayed to anyone on the Web.
The Test SLAC Home Page and those hanging only off that are another exception to being located in the production WWW space. They reside in a separate test space in UNIX to be determined.
Personal home pages are a third exception and reside in the person's
$USERNAME is the user's UNIX username,
$FILENAME is the name of the user's home page, usually
Generally speaking, there should not be links from production space to files in a person's home directory. That space is for testing and sharing informally.
/grp/$CODE, where $CODE is usually the two or three character BINLIST code. There are currently seventy-four of these in use. (See "Appendix A.")
From other contexts these codes are often already recognized by SLAC people, e.g., cd, pur, or scs. The BINLIST codes frequently focus on operational components of the SLAC organizational structure that are less likely to change than the hierarchical levels above them. In any case, keeping the hierarchy flatter means there are fewer components subject to change than if the name reflected all levels of today's organization chart.
There may be a few exceptions to using $CODE. For example, the
BINLIST code for the SLAC Library is lib and for TechPubs is pub
but these have other contexts in UNIX (e.g.,
/usr/local/pub). Also, the group may be particularly identified
with its name more than its code, e.g., the Library.
/pubs/slaconly/tip. Note, however, that users with appropriate AFS privileges may read any file in
/afs/slac/wwwspace including those with "slaconly" in their names.
Remember that by default all files in SLAC WWW space are visible to anyone using the Web around the world.
/grp/scs/net/figurefor figures that are displayed using Tony Johnson's CGI script. Being consistent helps people recognize directories and files when they encounter them or even unearth them via a
/slac/www/resource/resource.html. The "master" file may or may not be a home page. It is the file you want someone trudging down the file hierarchy to look at first for an understanding of what the subdirectory's all about. Sometimes a subdirectory may not (yet) have a "master" file, e.g.,
/slac/www/wwwtech/wwwstyle. Sometimes a home page, e.g.,
home.html, may be more appropriate.
In any case,
index.html is not appropriate since it is used by
various servers to show those files in the subdirectory that
may be displayed to the Web and suppress the automatic index
(specified, if enabled, by a terminal
/ on the URL
for other than the server default home page).
$PATH). Besides, it's not always possible to anticipate "correct" file name capitalization, even if you were to memorize The Chicago Manual of Style because of the limits on UNIX names. Using a consistent naming strategy saves time and frustration because it often results in reduced "finger jitter" when you try to anticipate the capitalization as you enter the names and, in the end, a total of fewer commands entered to access the files.
Some key pages:
slac.html the default SLAC Home Page /slac/disclaimer.html the SLAC disclaimers /slac/slacinst/institution.html the SLAC Institutional PageSome first-level subdirectories (functional first):
/accel for accelerator /archive@ " archives /bis " business information systems /comp " computing /emp " employment /esh " environment, safety, and health /exp " experiment (multi-institutional) /gen " general information /library " library /phys " physics /pubs " SLAC publications, images,... /slac " SLACwide information /spires " specifically SPIRES applications ... " more functional categories /org " organization-specific information /grp " group- or department-oriented information
Some second-level subdirectories (functional first):
/accel/pepii (multi-institutional) /archive/1994 /archive/1995 /bis/acct /bis/budget /bis/commits /bis/pers for personnel systems /bis/procure /bis/snap /bis/stores /comp/future /comp/intro /comp/mac /comp/net /comp/pc /comp/phys /comp/security /comp/telecom /comp/unix /comp/vendor /emp/emp-opp for employment opportunities /esh/bull /esh/slaconly /exp/e143 /exp/e144 /exp/e154 /exp/mq /exp/sld /gen/area for Local Area Resources /gen/edu /gen/map /gen/meeting /gen/tour /gen/visit /library/libnews.html /pubs/beamline /pubs/figure /pubs/slaconly /slac/hottopic /slac/slacinst /slac/www /spires/doc /spires/tool /spires/form /org/chart /grp/bbr (SLAC group) /grp/cd /grp/efd /grp/mfd /grp/pep (SLAC group) /grp/per /grp/scs /grp/thpA few lower-level subdirectories (functional first):
/bis/procure/req/slaconly /comp/intro/scsc-serv /comp/telecom/phone-dir /comp/telecom/phone-users-guide /exp/sld/figure/top20 /gen/meeting/ssi /pubs/figure/top20 /slac/www/gen /slac/www/resource /slac/www/resource/icon /slac/www/stats /slac/www/swug /slac/www/tool /slac/www/tool/search /slac/www/wwwpolicy /slac/www/wwwstyle /slac/www/wwwtech /slac/www/wwwtech/doc /slac/www/wwwtech/doc/notes /grp/scs/net /grp/scs/scsc /grp/scs/systemsA few examples of conventional file names:
/accel/pepii/home.html /slac/www/resource/resource.html /grp/scs/mission.html /grp/scs/orgchart.psSome exceptions:
For more information on installing pages, see
In the short run Joan Winters has agreed to serve as the registrar
with a backup registrar in the works and Pat Kreitz as the "higher
authority." In the normal course of events, one working-day
naming turnaround is the goal.
A place or places for source, .../src/..., should be provided in this
WWW AFS name space for files that are not self-defining, e.g., for
.ps or .pdf. In some cases a pointer file to where the source is
kept may suffice, but this may well prove to be less stable
It is also recommend that SLAC develop tools to ease migration of pages
through the system, including providing for file/URL renaming over the
years. Cleaning out the obsolete files (and sometimes putting them into
/archive/$YYYY, where $YYYY is the year of last update) will keep
the WWW information space easier to read and use by maintainers and
then by users.
Recommendations in Closing
It is recommended that subdirectory names at the first two WWW levels
be designed with a "WWW AFS Registrar" designated by the WWW Policy
Group, who works to keep the high level taxonomy sensible and
consistent in light of specific user needs and system requirements.
Groups may find designating their own group registrars (or
This work is an outgrowth of an effort started by Tony Johnson. See
"New URL Scheme for SLAC WWW Server".
He has continued to be very
helpful in discussions along the way. In addition, real world
examples provided by Ilse Vinson, Jay Venti, Brooks Collins, PA
Moore, Laurie Gennari, Diana Gregory, George Crane, and others have
helped significantly to flesh out the model. Feedback from the WWW
Technical Committee has been very useful in developing some of the
concepts. Any inadequacies in the document are, of course, my own.
In the short run Joan Winters has agreed to serve as the registrar with a backup registrar in the works and Pat Kreitz as the "higher authority." In the normal course of events, one working-day naming turnaround is the goal.
A place or places for source, .../src/..., should be provided in this WWW AFS name space for files that are not self-defining, e.g., for .ps or .pdf. In some cases a pointer file to where the source is kept may suffice, but this may well prove to be less stable over time.
It is also recommend that SLAC develop tools to ease migration of pages through the system, including providing for file/URL renaming over the years. Cleaning out the obsolete files (and sometimes putting them into /archive/$YYYY, where $YYYY is the year of last update) will keep the WWW information space easier to read and use by maintainers and then by users.
The purpose of the
/archive hierarchy is for important
files that no longer have a current use, e.g., pages for 1995's
"Take Our Daughters to Work Day", which is past,
or "The SLAC WWWizards" page, which SLAC no longer links but has historical
importance. This hierarchy is like a records storage facility for important
documents that you no longer keep in your office. It is not intended to be
Another category of old documents is those still having some clear amount of
use, e.g., an archive of old "list" email.
Consider creating a
sub-directory below the topics's major directory for these items.
AAO Affirmative Action Office ACC Accounting Office AD Accelerator Department BAS Business Applications Support Group BBR BABAR BSD Business Services Division BU Budget Office CAF Cafeteria CB Crystal Ball Project CD Controls Department CG Computation Research Group CMS Central Lab Machine Shop CYE Cryogenics Engineering CYO Cryogenics Operations DO Director's Office DOE U.S. Department of Energy EA Experimental Group A EB Experimental Group B EC Experimental Group C ED Experimental Group D EE Experimental Group E EFD Experimental Facilities Department EG Experimental Group G EH Experimental Group H EI Experimental Group I EK Experimental Group K ESA End Station A Users ESH Environment Safety and Health Administration EWM Environmental Protection and Waste Management(ESH) FAC Facilities Office FD Palo Alto Fire Department Station 7 IBM International Business Machines IRM Information Resource Management and Technology Transfer IS Information Services KLY Klystron and Microwave LHT Liquid Hydrogen Targets LIB Library LTR Low Temperature Materials Research M-2 Mark II Experiment MD Mechanical Design ME Mechanical Engineering/Alignment MED Medical Department MET Metrology MFD Mechanical Fabrications Department MU Mechanical Utilities NPS Nuclear Physics at SLAC OHP Operational Health Physics (ESH) PAD ESH Planning and Assessment Department PAO Public Affairs Office PCD Power Conversion Department PE Plant Engineering PEL Physical Electronics PEP Positron Electron Project PER Personnel Department PMS Plant Maintenance Services PRC Property Control PUB Publications PUR Purchasing RD Research Division RPG Radiation Physics (ESH) SCS SLAC Computing Services SEC Security SHA Safety, Health and Assurance Department SLC SLAC Linear Collider Project SLD SLAC Large Detector SSP Summer Science Program SSR Stanford Synchrotron Radiation Lab TD Technical Division THP Theoretical Physics TPC Time Projection Chamber TR Travel TSP Accelerator Theory and Special Projects TT Tiger Team VAC Vacuum Group