I.R.I.S. Readiris 14 for Mac User Guide - Manual (Page 57)

Section 5: Selecting the Recognition Options
52
 Cmd-click to select the Secondary languages.
The list of secondary languages changes depending on the
selected primary languages.
Note: do not select languages that do not apply; the bigger the
character set, the slower the recognition and the higher the risk
of OCR errors.
D
OCUMENT
C
HARACTERISTICS
(This section does not apply when processing Asian or Hebrew
documents)
Next to the document language, other document characteristics such
as the Font type and Character pitch play an important role in the
recognition process.
Font type
Readiris distinguishes between "regular" and dot matrix printed
documents. Dot matrix symbols (of the type 9 pin) are made up of
isolated, separate dots.
Special segmentation and recognition techniques are required to
recognize dot matrix documents and need to be activated.