What is the meaning of 'T' in the execution permissions of a directory?

"t will be in place of others permission and in place of execute permission. So it means that t is for execute + sticky bit. T means only sticky bit without execute permission.

Example:

dr-xr-xr-t 2 scm scm 4096 Feb 15 17:48 log
drwxr-xr-T 2 scm scm 4096 Feb 15 18:04 rpm

Here, log has execute + sticky bit (others). rpm has only sticky bit."