This is a Multi-way Club system, and 1 is forcing. It still promises a doubleton in all variants (some people also include the bothersome 4441 with short ).
Opening bids
1
12 - 14 balanced
18 - 20 balanced
12+ HCP, 4441, not short
12+ HCP, 5+
1
12+ HCP, 5+ or 4 4 4 1
1
12+ HCP, 5+
1
12+ HCP, 5+
1NT
15 - 17 balanced
2
GF
23 - 24 balanced
Weak Two in
2
Multi: Weak Two in /, 25 - 26 balanced or SemiForcing /