PK_ for primary keys
UK_ for unique keys
IX_ for non clustered non unique indexes
UX_ for unique indexes
DF_ for default value
All of my index name take the form of<index or key type>_<table name>_<column 1>_<column 2>_<column n>
<index or key type>_<table name>_<column 1>_<column 2>_<column n>