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Sometimes the signs will appear on their own (like the first example), or else they will be a small addition to an existing sign with many directions as you can see in the example below.
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Occasionally I have tried to follow the signs to see where they lead to, but always I have given up after several left/right turns that don't seem to be leading to any particular direction.
Can anyone take me out of my misery and tell me what the signs mean?
Are they a Dublin phenomenon or do they appear in other parts of Ireland? Can the y be found in other countries?