BluetoothDevice.uuids - Web APIs
the bluetoothdevice.uuids read-only property lists the uuids of gatt services provided by the device, that the current origin is allowed to access.
... syntax var uuids[] =​ instanceofbluetoothdevice.uuids returns an array.

Generating GUIDs
sfink's update-uuids will change the uuid for a given interface and all of its descendants, updating all *.idl files within a directory tree.
... online tools http://mozilla.pettay.fi/cgi-bin/mozuuid.pl guidgen guidgen.exe, part of microsoft visual studio, can generate uuids in this format.

Bluetooth.requestDevice() - Web APIs
this filter consists of an array of bluetoothserviceuuids, a name parameter, and a nameprefix parameter.
... optionalservices[]: an array of bluetoothserviceuuids.

BluetoothDevice - Web APIs
gatt; readonly attribute frozenarray uuids; promise watchadvertisements(); void unwatchadvertisements(); readonly attribute boolean watchingadvertisements; }; bluetoothdevice implements eventtarget; bluetoothdevice implements bluetoothdeviceeventhandlers; bluetoothdevice implements characteristiceventhandlers; bluetoothdevice implements serviceeventhandlers; properties bluetoothdevice.id read only a domstring that uniquely ...
... bluetoothdevice.uuids read only lists the uuid's of gatt services provided by the device, that the current origin is allowed to access.

Index - Web APIs
305 servicedata api, bluetooth, bluetoothadvertisingdata, non-standard, obsolete, property, reference, servicedata the servicedata read-only property of the bluetoothadvertisingdata interface returns a map that relates uuids to arraybuffers.
... 312 bluetoothdevice.uuids api, bluetoothdevice, experimental, property, reference, uuids, web bluetooth api the bluetoothdevice.uuids read-only property lists the uuids of gatt services provided by the device, that the current origin is allowed to access.

context-menu - Archive of obsolete content
const { getmostrecentbrowserwindow } = require("sdk/window/utils"); var cm = require("sdk/context-menu"); var uuid = require('sdk/util/uuid').uuid(); var uuidstr = uuid.number.substring(1,37); cm.item({ data: uuidstr+"this is a tooltip", label: "just a tigger, will never show up", contentscript: 'self.on("context", function(){self.postmessage(); return false;})', onmessage: function(){ var cmitems = getmostrecentbrowserwindow().document.queryselectorall(".addon-context-menu-item[value^='"+ uuidstr +"']"); for(var i=0; i < cmitems.length...

util/uuid - Archive of obsolete content
generate or parse uuids.

Low-Level APIs - Archive of obsolete content
util/uuid generate or parse uuids.

The Essentials of an Extension - Archive of obsolete content
unix-based systems have a command line tool called uuidgen that generates uuids.

Index - Archive of obsolete content
130 util/uuid generate or parse uuids.

Microsummary topics - Archive of obsolete content
the value of the attribute must be a valid uri, but you can specify an arbitrary identifier using a urn, for example: urn:{835daeb3-6760-47fa-8f4f-8e4fdea1fb16} to guarantee uniqueness, use urns containing uuids generated by the nsuuidgenerator component.

Modularization techniques - Archive of obsolete content
the ids are unique 128 bit numbers that are based on uuids.

The First Install Problem - Archive of obsolete content
unlike uuids, plids are human readable, and not lengthy "garbled" strings.

Reviewer Checklist
idl uuids are updated when the interface is updated.

Creating the Component Code
all of the 128-bit numbers used in xpcom - the class and the interface ids - are examples of uuids, or universal unique identifiers, which were discussed in object interface discovery.