Explanations of words and terms used in London rental business

Adjacent Contiguous, adjoining, neighboring
Application Form A form completed by an applicant on a property which collates the relevant information about the background of a prospective tenant and which is then usually used as a basis for obtaining references.
Borough An area of the town with local government
Council Tax A local tax, set by councils, to help pay for local services like policing and refuse collection; applies to all properties
Council Tax Band Determines how much Council Tax you pay
Decent Homes By 2010, 95% of all social housing in the UK will need to be of a minimum standard.
Direct Associate A brother, sister, husband, wife, partner (co-habitee in an intimate relationship), aunt, uncle, nephew, niece, parent, grandparent, children or grandchildren.
DSS Tenant A tenant, who gets benefits from the government, specifically from the Department of Social Security
EPC Energy Performance Certificate – shows how energy efficient the property is on a scale of A-G, with A being the most efficient.
Guarantor Someone who makes a binding commitment to fulfil agreed obligations (financial or otherwise) of a tenant who reneges on, or breaches, the terms of their tenancy agreement.
HMO Houses in Multiple Occupation
Holding Deposit This is held till you get your paperwork and finances ready. Usually 1 weeks rent. The normal holding period is 1 week. Make sure to get a written note of the received sum, date, property address, payee name and signature. Not to be returned should you decide to back out of the deal. If the deal is off because of the landlord or estate agent – ask your money back. Write a formal letter if necessary or write a claim HERE.
Inventory & Schedule of Condition In the letting industry these are encompassed in, and considered to be, one document. This is a critical document in the process of letting or renting a property and helps protect landlord, agent and tenant. An Inventory is an itemised listing of the items (contents, fixtures and fittings etc) in a property and the integral Schedule of Condition element describes the state of the property, including walls, floors, ceilings and externally, the garden and garage; and their (the items), state.
Inventory Clerk A person, usually with a degree of appropriate experience and or training, who prepares an Inventory/Schedule of Condition prior to commencement of a tenancy; checks the document at the end and prepares a summary of disrepair or damage etc; and updates the document as appropriate before re-letting.
Landlord A person or persons (or company) who at any relevant time own, or have a formal interest in, the property that gives them the right to possession of that property.
Letting Renting out property( real estate).
Letting Agent Professional
Letting Fees & Charges Money, or a share of money, due to an agent for the provision of or for the arrangement of, agreed services.
PCM Rent Per Commencing Month
Power Shower A shower using a pump to boost the flow of water to give a powerful shower spray (diydata.com).
PW Per Week
Refurbishment repairing or remodeling the property
Rental Property an apartment or a house offered or given for rent
Rent a Room Scheme Optional exemption scheme that lets you receive a certain amount of tax-free ‘gross’ income (receipts before expenses) from renting furnished accommodation in your only or main home.
Sale and Rent Back Property transaction whereby firms buy homes from individuals, usually at a discount, and then allow those individuals to stay on in the property as tenants.
Social Rented Housing The role of social rented housing has been, and remains, to provide good quality housing at below market rents for those otherwise unable to afford decent housing.
Tenancy Agreement A legally binding document, which creates the contract between Landlord and Tenant and governs the respective obligations and responsibilities of both parties.
Tenancy Deposit Bond Tenant’s money paid by a tenant, held for the term of a tenancy, to be subsequently allocated against breaches of the tenancy agreement, in particular, damage, cleaning or non-payment of rent.
Tenancy Deposit Scheme From 6 April 2007, all deposits (for rent up to £25,000 per annum) taken by landlords and letting agents for Assured Shorthold Tenancies in England and Wales, must be protected by a tenancy deposit protection scheme.
Tenant A person or persons who at any relevant time have the lawful right to occupy a property, under the terms of a tenancy agreement, for which rent is usually paid. 
TPOS The Property Ombudsman Appointed to look into complaints about an organisation. Using an ombudsman is a way of trying to resolve a complaint without going to court.

SOURCES:
Directgov
The Supply of Rented Housing 2007-08 House of Commons
ARLA Association od Residential Letting Agents