string not clear for a translator

[Federico Bruni]

I'm updating the italian language and I can't understand what this dash 
is about here:

$ git grep -n -A4 -B4 "Re-defining dash" lily/
lily/parser.yy-3316-// 
-----------------------------------------------------------------
lily/parser.yy-3317-// obsoletion handling, may be removed at some 
point (e.g. for 2.26)
lily/parser.yy-3318- } else if (scm_is_string (s)) {
lily/parser.yy-3319- string s_string = ly_scm2string (s);
lily/parser.yy:3320: @$.warning (_f ("Re-defining dash%s using a string 
is deprecated. \
lily/parser.yy-3321-Please try replacing \"%s\" by \\%s or run 
convert-ly.",
lily/parser.yy-3322- ly_scm2string ($1), s_string, s_string));
lily/parser.yy-3323- Music *a = MY_MAKE_MUSIC ("ArticulationEvent", @$);
lily/parser.yy-3324- set_property (a, "articulation-type", 
scm_string_to_symbol (s));

BTW, no space between dash and %s?