Boxes are written primarily in Dutch, with some English (song titles, etc). As so I (and other collector's I've spoken too) haven't yet seen 1st-Year Belgian box, it's reasonable to guess that these Dutch-only boxes sufficed for the Belgian market as well. 

1. Doll's name: Depending on the doll, reads: "________ van de Holograms/Misfits".  It is important to distinguish this from "von der Holograms/Misfits, as those are German boxes.
2. Cassette Tape Information: Song titles remain in English, the rest of the writing is in Dutch.
3. Hasbro Logo: the same as the US.
4. Truly Outrageous Tag: remains the same as the US, no difference.
5. Stock Number: Different system than US
6. Audition Contest Panel: has a short description of Jem and the Holograms (nothing to do with the audition contest)
7. Licensing information/Country of manufacture: reads "© 1986 MB/International BV/under Berne & Universal Copyright Convention./Made in Hong Kong/H32."  Notice the later date, US boxes typically are dated 1985.
8. Jemstar Points/Proof of Purchase; are there but with no explanation as to what they are on the box.

For more on Jem in The Netherlands, go here.

See the numbered example box to understand the numbering system described here.
Boxes are primarily in Dutch, with some English text.
1. Doll's name: Jem/Jerrica (same as US)
2. Jem "star" logo: Same as US, translated into Dutch.
3. Hasbro Logo: the same as the US.
4. Truly Outrageous Tag: same as US
5. Stock Number: 6000's European system, shown on top flap and under Jem star points on the back.
6. Audition Contest Panel: I don't understand Dutch, but it looks like a brief description of Jem and Jerrica's dual personality.
7. Licensing information/Country of manufacture: side panel area is blank.  The licensing information instead is found under the contents listing on the back.  "© 1986 Hasbro een divisie van MB International BV - Utrecht/Brussel under Berne & Universal Copyright Convention."  The Brussels mention makes me think these same dolls were sold in Belgium; in fact this specific doll was purchased in Belgium.
8. Jemstar Points/Proof of Purchase; are present.
Other: like the US box, Jem/Jerrica boxes have some additional text on the back, relating to her batteries (by Jerrica's leg in the drawing). 

1. Doll's name: Depending on the doll, reads: "________ des/van de Holograms" or "________ des/van de Misfits". 
2. Cassette Tape Information: Song titles remain in English, the rest of the writing is in French and Flemish.
3. Hasbro Logo: the same as the US.
4. Truly Outrageous Tag: font is smaller, and reads below that "Vraiment Extravagante." (like the Canadian boxes)
5. Stock Number: Different system from the US
7. Licensing information/Country of manufacture: © 1986 Hasbro Inc./Pawtucket RI 02862/Importateur pour la Belgique:/Hasbro MB S.A. Digue du/Canal, 109-111, 1070 Bruxelles/Invoerder voor België:/Hasbro MB. N.V. Vaartdijk/109-111 1070 Brussel H44 (Raya). Clash's has the same general information & addresses but in a different order.
8. Jemstar Points/Proof of Purchase; Are there, with no indication as to why.

Name Changes:
Flash 'n Sizzle Jem/Jerrica was known as Rock 'n Flash Jem/Jerrica
Glitter 'n Gold Jem/Jerrica was known as Rock 'n Gold Jem/Jerrica
Glitter 'n Gold Rio was known as Rock 'n Gold Rio
Rock 'n Curl Jem was known as Rock 'n Roll Jem.

For more on Jem in Belgium, go here.

All I know is from the box photo and information Dutch fan Stefan has sent me: " 2e year dolls in holland were almost only sold with dutch lanuage only but sometimes we got som e english boxes also. the names were never changed in holland so glitter n gold was kept glitter n gold. the gng roadster and flash nsizzle jem and waterbed were never for sale in holland! i have this comfirmed from mb international because i wrote them a letter back in 88 and the send me a list of stuff the sold in holland."

1. Doll's name: For 1987, so far, I've only seen Rock 'n Curl Jem, Glitter 'n Gold Jem, and Clash in purely Dutch (not Belgian) boxes. They remained the same as the US names.
2. Cassette Tape Information: Unknown
3. Hasbro Logo: Unknown, probably the same as the US.
4. Truly Outrageous Tag: remained "Truly Outrageous!"
5. Stock Number: Different system from the US
7. Licensing information/Country of manufacture; © 1986 MB International BV under/Berne & Universal Copyright/ Convention. Importeur voor België: Hasbro-MB N.V.,/Louizalaan 386, 1050 Brussel./MB International B.V., Utrecht, Holland./Made in China H4
8. Jemstar Points/Proof of Purchase: information needed; likely the same as the first year Italian dolls

For more on Jem in The Netherlands, go here.

• Stickers (sheet, blue background)
• Mailing Labels
• Bedspread and Pillowcase
• Puzzles boxed, MB, 200 pcs, also available in the UK:

• Jem in Award Night in front of the Rockin' Roadster (mostly redrawn box art)
• The Misfits on stage (redrawn box art)
• Jem & The Holograms on stage (redrawn box art)
• Rio, Jem & The Rockin' Roadster (mostly original looking drawing)

• Jem Comic Books, translated into Dutch. Here's one: Omnibus #2.