U.K. Data Protection Act (1998), 75, 292
U.K. Disability Discrimination Act, 170
UML (Unified Modeling Language) standard, 74
unaddable amounts, not sorting on, 270
unaddable data, 262, 270, 271
unapproved actions, storing, 323
unavailability, surreptitious, 221, 224–225, 238
unavailability window, 219
undecipherable form of passwords, 292
Unified Modeling Language (UML) standard, 74
uninstalling, 277, 279
unique identifiers, 98–99
for requirements, 13, F-33, F-36–F-37
scheme for assigning, 97
unique interface IDs, 52
unit IDs for organizations, 329
units, associated with values, 87
Universal Time Co-ordinated (UTC), 90, 92
unknown information, 160
unpaid fees, tracking, 336
unparochialness
content requirements, 256
examples of, 257
extra requirements for, 257–260
specifying, 254–255
templates for, 256
testing, 260–261
unparochialness requirement pattern, 254–261
unsigned numbers, data type, 87
upgrade from any previous version requirement, 277
upgrade instructions, documentation requirement, 83
upgrade requirements for an interface, 59–61
upgrades
as downtime, 225
duration of, 230
frequency of, 229–230
preparation for, 230
scalability requirements and, 245
testing, 278
uninstalling, 277
upgrading, 276
of an interface, 57
specifying requirements for, 277
by versions, 278
urgency of a requirement, F-39
U.S. Rehabilitation Act, Section 508, 170, 175, 186
usability, 168, 169, 175, 185, F-70. See also accessibility
use cases
compared to user stories, F-24
defined, F-13
for requirement patterns, 37–38
writing, F-13–F-14
use case diagram, F-13
users
allocating IDs to, 99
availability of system to. See availability
behavior of, 212–213
counting dynamic, 213
forcibly ejecting, 214
geographic distribution of, 209
limiting number of, 214
number of active, 149
with specific needs, 168, 169, 172, 174–175, 183–184. See also accessibility
as system, 171
wait time warnings for, 203
user access state, specifying, 143
user access via Web browser, 68
user accountability, 282
user actions, 147, 148
user authentication, described, 281, 282
user authentication requirement pattern, 295–305
user authorization
described, 281, 282
inquiry requirement, 317
user authorization requirement pattern, 305–307
user classes, 285
user colors, accessibility requirements, 180
user de-registration, 287, 290
user experiences, distinct, 261, 267–269
user function domain, 29
user function requirement pattern, 155–190
user IDs, requirement for no special, 293
user interfaces
allowing user to adjust to, 175
capabilities, 187, 188
inter-system interface requirement pattern not used for, 52
multiness in, 267
semantic requirements, 178, 186
tailoring for specific needs, 183–184
user interface designer, F-15
user interface infrastructure, 155, 187–189
user preferences, 132–133
user registration, 281, 282
user registration requirement pattern, 284–295
user response time, 196, 201
user roles, 15, 316, F-55
user sessions
allocating, 214
created by authentication, 296
ending, 298, 300–301
viewing, 298, 303–304
user stories, 9, 10, F-24, F-26
user times per time zone, 93
user-accessible information, viewing of, 160
users
blocking, 298, 302–303
details about, 285
performing their own registration, 284
protection of, 298, 301
registering, 284
special processes for new, 287, 293–294
UTC (Universal Time Co-ordinated), 90, 92