Please don't make your database query too broad.

 For example, a search of

 "Everything, Everywhere, All Services, Any type"

 causes a lot of problems. First it puts a huge load on the server because it has
 to dynamically build the display page. Second it puts a huge load on the database
 engine which can cause it to time out. Third it can cause your browser to hang or
 crash due to the extreme size of the html table generated for the output.

 I don't care for ambiguous FCC-style coding, therefore usage codes are as follows:

BIZ - Business
TAX - Taxicabs
TRA - Transit
RRD - Railroad
AIR - Civilian aircraft
MAR - Marine
MED - Media
PHO - Telephone (MTS, IMTS, Cellular, Airphone)
PAG - Paging
RCC - RCC (I use this code to signify an RCC channel thats mixed phone/paging)
POL - Police
FIR - Fire
CIT - City
COU - County
STA - State
DNR - State DNR
DOT - State DOT
FED - Federal
MIL - Military
HOS - Hospital
AMB - Ambulance
FFD - Fast Food
CBR - CB Radio
ITN - Itinerant
ZZZ - Miscellaneous
UNK - Unknown

PL/Mode column is used as follows:
 Blank - means narrow FM or unknown. Since most listings are narrow FM I didn't
         see a point in entering it a zillion times.
  CSQ  - means narrow FM and they use carrier-squelch
 85.4  - A decimal number like this means narrow FM with tone-based PL.
 NODP  - Means no decodable PL/DPL tone, but not 100% sure if its carrier-squelch.
 D732  - Anything starting with "D" means narrow FM with DPL.
 3D1C  - Four digit numbers are a trunked system ID
 TONE  - Means tone burst
 GDTN  - Means guard-tone
  P25  - P25 digital
 N123  - Anything starting with "N" means its the NAC code for P25 digital.

Type column is used as follows:
S - Simplex
BR - Broadcast
B - Beacon
R - Repeater Output
i - Repeater Input
L - Link transmitter
SR - Simplex Repeater
/ - Paired duplex or half-duplex, like VHF Taxis, 800mhz Cellular, or ship-shore
TR - Motorola Type 1 or 2 trunked
LT - LTR trunked
M2 - Multinet-2 trunked
ED - EDACS trunked
NX - Motorola Iden (Nextel) trunked
D - Digital (pagers)
V - Voice (pagers)

Abbreviations used in the "Notes" field:
CWID - Morse Code identifier
A/P - Autopatch (telephone patch) or Airport
ATC - Air traffic control
(N) - Used at night. A small notation I use while trying to figure out who
 is using a particular freq.
(NE) - Not English - Usually used when noting a shortwave transmission that
 is in some foreign language that I don't recognize.
NBDP - Narrowband direct printing (marine teletype)
* - Anything with a star in front of it means unverified data, for example
 something I got from the FCC database but haven't heard anybody actually
 using the freq.

Other comments:
 I could have made an individual column for every imaginable category or detail
however this format makes it easy to print out (which was the original purpose
of this database). Thats why I have multi-use columns like the "PL/Mode" column.

 Multiple-category items are coded as I saw fit. For example Harborview Hospital
800mhz simplex is coded as "county" rather than "hospital" because that way it
will be displayed in a county-only service search along with the trunked system

 All King Co Trunked Radio System freqs are coded as County even though the city
of Seattle and the EPSCA cooperative run their own subsystems. This was done to
simplify searching the database.

 KCTRS sites outside of King County (Apple Cove, etc.) are still coded as King
County to simplify database searches.

 Port of Seattle is coded as "County". Yes I know they are a Port Authority and
not a county agency. 

 LTR systems are assigned arbitrary system ID's so that frequency groups at a
particular site can be determined. A multiple-site system ID will be the system
number, a dash, and then a site number (like 3-2).

 Motorola trunk systems will have the site number in the "channel" column. The
site number might numerically be off by 1 depending on whether you go by the
way Motorola numbers them or the way "Trunker" reads them off the control

 Trunk talkgroups are listed with a freq of "99999". This was done to keep
some search-by-frequency results from looking messy. The talkgroup number
will be in the "callsign" field.

 The original scope of this database was based on what can be received in King
and Snohomish county, regardless of where the originating point of transmission
is. I have recently changed the format to accomodate frequencies from anywhere
in the world.

Some columns have multiple uses to make the most efficient use of screen
real-estate. For example the "callsign" field is also used for talkgroup ID's.

 I'm sure there are many more little things I'm forgetting about right now.
Whatever the case, there is a logical reason behind codings that might otherwise
appear to be either incorrect or misleading.