Most of Indonesian people who live in Iceland will travel outside of the country at one time or another. When a child (anyone who is under the legal age of 18, according to Icelandic law) is travelling abroad alone, with only one parent/guardian, with friends or relatives or with a group, it is necessary to carry a consent letter.
This form needs to be filled out completely, stating the name of parent/guardian giving consent, contact details, identification number, details of person the child is travelling with, and travel plans (including travel date and destination). Then it has to be signed in front of two witnesses or public notary (recommended).
Indonesian Community in Iceland 
Good blog and nice information
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