svn:executable properties by updating the file mode directly before adding it to the Git repository.
GitHub internally tracks the mime-type properties of files and the commits that added them.
If you've set files and directories to be ignored in Subversion, GitHub will track them internally. Files ignored by subversion clients are completely distinct from entries in a .gitignore file.
GitHub doesn't currently support
svn:global-ignores, or any properties not listed above, including custom properties.