The calculator in question is the TNM Classification for Gallbladder Cancer. TNM stands for Tumor, Node, Metastasis, a system used to classify malignant tumors. This specific classification is used for patients diagnosed with gallbladder cancer. 

The TNM Classification for Gallbladder Cancer is a staging system that helps clinicians determine the extent of the cancer, its spread, and the appropriate treatment options. It is based on three key pieces of information: the size and extent of the tumor (T), whether the cancer has spread to the lymph nodes (N), and whether the cancer has metastasized to other parts of the body (M). 

The clinical utility of this calculator is to guide treatment decisions and provide prognostic information. It helps in planning the surgical approach, deciding whether additional treatments like chemotherapy or radiation are needed, and predicting patient outcomes. 

There are no specific exclusion criteria for its use, but it is most applicable to patients with confirmed diagnosis of gallbladder cancer. It is less useful in the early stages of disease when the extent of the cancer is not yet clear, or in patients with other types of gallbladder disease.

TNM classification for gallbladder cancer

# Criteria
 ## Tumor classification
A. Tx: Primary tumor cannot be assessed
B. T0: No evidence of primary tumor
C. Tis: Carcinoma in situ
D. T1a: Tumor invading lamina propria
E. T1b: Tumor invading muscular layer
F. T2a: Tumor invading perimuscular connective tissue on peritoneal side, without involvement of serosa (visceral peritoneum)
G. T2b: Tumor invading perimuscular connective tissue on hepatic side, with no extension into liver
H. T3: Tumor perforating serosa (visceral peritoneum) and/or directly invading liver and/or one other adjacent organ or structure (such as stomach, duodenum, colon, pancreas, omentum, or extrahepatic bile ducts)
I. T4: Tumor invading main portal vein or hepatic artery or invading >= 2 extrahepatic organs or structures
## Lymph node classification
J. Nx: Regional lymph nodes cannot be assessed
K. N0: No regional lymph node metastasis
L. N1: Metastases to 1-3 regional lymph nodes
M. N2: Metastases to >= 4 regional lymph nodes
## Metastasis classification
N. M0: No distant metastasis
O. M1: Distant metastasis present

# Conditions
- C and K and N
- (D or E) and K and N
- F and K and N
- G and K and N
- H and K and N
- (D or E or F or G or H) and L and N
- I and (K or L) and N
- ((C or D or E or F or G or H or I) and M and N) or ((C or D or E or F or G or H or I) and (J or K or L or M) and O)
- true