I have just had an inquiry about the location of a house described in the 1891 census as "8 Court No 10, Vicarage Cottages" in the parish of St Mary, Watford.
Care must be taken with such entries. For each household the census enumerator gave an enumeration number, in this case 197, which was only to help him check the paperwork was correct and can otherwise be ignored.
"Court 10" may also be a temporary name given for the enumerator's benefit to a court which was normally called "Vicarage Cottages." The courts were often little more than a collection of inhabited buildings in what had once been the back yard of a house or business facing onto the road. Most were what we would now called slums - and have long been demolished and the site reused in some way. Sometimes the court would be named after the owner - and I suspect this is the case with "Gregory's Yard." People using the census are often confused because a court may well be given a different name in different censuses.
The first thing to do when you are trying to locate a census property is to look at the front of the census book where you will find a description of the area covered by the particular enumeration book. In this case the description show that the enumeration area ends with "... to Mr Upson No4 Church Street, the Vicarage, Free School and Courts No 10 and 12." This would suggest that "Vicarage Cottages" might well be a court associated with the Vicarage,
It is often possible to get the same information by simply looking at the pages on either side of the property you are interested in. In this case the situation is complicated because all that is shown between Mr Upson's house and Court 10 are three unoccupied houses where no-one was living on the night of the census. These unoccupied house may well have included the Vicarage and a house for the headmaster of the Free School.
For more information on relating census locations to maps see