[Inkscape-translator] question about a variable

I like to know what can be the %s in this string:

#: ../src/sp-flowtext.cpp:381 #, c-format msgid "<b>Flowed text</b> (%d character%s)" msgid_plural "<b>Flowed text</b> (%d characters%s)" msgstr[0] "" msgstr[1] "" msgstr[2] ""

Thank you, Cristi