string of flags
A string of flag or pennants strung together for decorative purposes.
Strings of flags are sometimes called "bunting", though that's a much broader term that also includes other types of fabric decorations. If the flags are of countries, use the flags of all nations tag.
Example
See also
The following tags are aliased to this tag: bunting (learn more).
The following tags implicate this tag: flags_of_all_nations (learn more).

