What do the codes mean in Box 13 of the K-1 for partnerships?

Other deductions
A: Cash contributions (60%)
B: Cash contributions (30%)
C: Noncash contributions (50%)
D: Noncash contributions (30%)
E: Capital gain property to a 50% organization (30%)
F: Capital gain property (20%)
G: Contributions (100%)
H: Investment interest expense
I: Deductions--royalty income
J: Section 59(e)(2) expenditures *
K: Excess business interest expense (EBIE)
L: Deductions--portfolio income (other)
M: Amounts paid for medical insurance
N: Educational assistance benefits
O: Dependent care benefits
P: Preproductive period expenses
R: Pensions and IRAs
S: Reforestation expense deduction
V: Section 743(b) negative income adjustments *
W: Soil and water conservation
X: Film, television, theatrical, and sound recording production expenditures
Y: Expenditures for removal of barriers
Z: Itemized deductions
AA: Contributions to a capital construction fund (CCF)
AB: Penalty on early withdrawal of savings
AC: Interest expense allocated to debt-financed distributions
AD: Interest expense on working interest in oil or gas
AE: Deductions - portfolio income
ZZ: Other

* Not supported

See the Schedule K-1 (Form 1065) instructions  for more info about these codes.