Mode 1777 has sticky special digit 1 and ordinary digits 7, 7, 7. It is a useful conversion example because the last symbolic position represents both others execute and sticky. The scenario describes a shared directory concept; it does not recommend creating one in an unknown environment.
1 · 7 · 7 · 7
Special digit 1 enables sticky but not setuid or setgid. Each ordinary 7 enables read 4, write 2, and execute/search 1 for owner, group, and others. Before placing the special marker, the ordinary display is rwxrwxrwx.
Sticky plus others execute produces lowercase t
Sticky occupies the final execute position. Because the others execute bit is also 1, x becomes lowercase t and the result is rwxrwxrwt. If sticky were set while others execute were absent, the final marker would be uppercase T, as in 1700 → rwx-----T.
Sticky narrows deletion; it does not make the directory safe
On a Linux directory, sticky restricts unprivileged removal or renaming to the entry owner, directory owner, or a privileged process. It does not remove read, write, or traversal bits, validate ownership, control file contents, replace ACLs, or make arbitrary shared storage appropriate. Confirm the real environment before applying 1777.