Space type enumeration. See AT_REC_LETTER.SpaceType.

Values:

IG_REC_SPC_SPACE	Real space.
IG_REC_SPC_TAB	Tabular.
IG_REC_SPC_LEADERDOT	Dot leader.
IG_REC_SPC_LEADERLINE	Line leader.
IG_REC_SPC_LEADERHYPHEN	Hyphen leader.