line 1: Filename: [name]
line 2: Organism: [name]
line 3: Accession Number: [accession]
line 4: Comment
Next lines give the sequence and structure:
[Base number] [BASE] [Link]
Exemple:

Filename: RNAExemple.bpseq
Organism: Exemple
Accession Number: E000001
This is an exemple of a bpseq file
1 A 0
2 A 9
3 C 8
4 C 7
5 U 0
6 U 0
7 G 4
8 G 3
9 U 2
10 G 0