user at the next successful signon. Too many password failures without a successful entry are reported to the system operator and still more password failures without a successful entry will cause the signon ID to be "locked out" until it is reset by business office staff. A short delay is introduced between failed password entry attempts to prevent large numbers of password "guesses" from being made quickly. Individuals can have multiple sign on IDs for use in different courses, different research projects, or with different funding sources (university, government, non-profit, industry, ...). The sharing of signon IDs by individuals is discouraged, but does occur. Signon IDs are grouped into projects. Each signon ID is a member of one and only one project. Project IDs, like signon IDs, are 4 characters long. Many projects are controlled by a "Project Leader" signon ID which can allocate resources to the accounts that are members of the project (within the resource limits allocated to the project) using the $ACCOUNTING MANAGEMENT command. Signon and project IDs are also used to control access to files and to send e-mail. With one exception there are no signon IDs with "special" privileges by virtue of the ID itself. Instead, flags can be set that allow specific signon IDs to: create public files and set public program keys, run with a zero or negative account balance, perform privileged operations, including: flagging files to run in system (unprotected) rather than user (protected) mode by default, use the PROT=OFF options on the $SET and $RUN commands, use the test command language subsystem ($#CLS), use privileged options of the $SYSTEMSTATUS and other command language subsystems (CLSs). The exception is the signon ID "MTS.", which can read, but not modify or permit, any file in the system regardless of ownership or permit status. The MTS. ID can also use the $SET FILEREF=OFF option, which prevents the file reference dates on files from being updated (useful when recovering from file system problems or investigating security issues). There is no ability for a program or user to assume the privileges of a signon ID other than the one that was used to sign on to the current session. Instead, programs and files may be permitted to specific signon IDs, projects, and program keys or to combinations of signon IDs, projects, and program keys. Terminal, batch, and server sessions MTS supports terminal, batch, and server sessions.