summarized by ChatGPT - FOLIO Circulation Rules

https://github.com/folio-org/mod-circulation/blob/master/doc/circulationrules.md

The circulation rules govern the application of loan policies based on a combination of criteria such as the patron's group and the item's material type, loan type, and location. The rules are designed to ensure that the most appropriate policy is applied in any given scenario, based on a hierarchy of criteria and priorities. The document explains several key concepts to understand how these rules work:

本文件概述的流通規則根據如讀者群組、物品的材料類型、借閱類型和位置等一系列標準來管理借貸政策的應用。這些規則旨在確保在任何給定的情境下，根據一定的標準和優先級層次結構，應用最合適的政策。該文件解釋了幾個關鍵概念以理解這些規則是如何工作的：

• Fallback Policy: A default policy applied when no specific rules match the given criteria. This ensures that there is always a policy in place, even if none of the more specific rules apply.
• 後備政策（Fallback Policy）：當沒有特定規則符合給定的標準時，將應用一項默認政策。這確保了即使沒有更具體的規則適用，也總有一項政策到位。

• Criteria and Criterium: The rules are based on various criteria (such as patron group, material type, loan type, and location), each of which is referred to as a criterium. These criteria are used to match specific policies to specific scenarios.
• 標準和標準細項（Criteria and Criterium）：規則基於各種標準（如讀者群組、材料類型、借閱類型和位置），每一個都被稱為標準細項。這些標準用於將特定政策與特定情境匹配。

• Combining Criteria: Criteria can be combined in rules using either a plus sign (+) or indentation, allowing for complex matching based on multiple factors.
• 組合標準（Combining Criteria）：可以使用加號（+）或縮進在規則中組合標準，允許基於多個因素進行複雜匹配。

• Priority and Decision Making:
• Criterium Type Priority: Criterium types are assigned a priority, and when multiple rules match, the one with the highest priority criterium type is selected.
• Rule Specificity Priority: The specificity of a rule, determined by the number of criteria it includes, also influences its priority. Rules with more criteria (hence more specific conditions) are given higher priority over those with fewer criteria.
• Line Number Priority: When rules have the same priority based on the above criteria, the line number of the rule can be used as a tiebreaker, with either the first or the last matching rule being selected depending on the specified line regulation.
• 優先級和決策制定（Priority and Decision Making）：
• 標準細項類型優先級（Criterium Type Priority）：標準細項類型被分配一個優先級，當多個規則匹配時，選擇優先級最高的標準細項類型的規則。
• 規則特定性優先級（Rule Specificity Priority）：一條規則的特定性，由它包含的標準數量確定，也會影響其優先級。包含更多標準（因此條件更具體）的規則具有比包含較少標準的規則更高的優先級。
• 行號優先級（Line Number Priority）：當規則基於上述標準具有相同的優先級時，規則的行號可用作決策點，根據指定的行規則選擇第一個或最後一個匹配的規則。

• Special Selectors: The document also discusses special selectors like "!" (negation) and "all", which can be used to fine-tune which items or patron groups a rule applies to. The "all" selector is particularly useful for adjusting rule priority without overly restricting the applicability of a rule.
• 特殊選擇器（Special Selectors）：文件還討論了像 "!"（否定）和 "all" 這樣的特殊選擇器，可用於微調哪些物品或讀者群組適用某條規則。"all" 選擇器尤其有用於調整規則優先級，而不會過度限制規則的適用性。

• Nesting and Hierarchies: Rules can be nested within one another to create hierarchies, allowing for the creation of complex decision trees that can handle a wide variety of scenarios with a high degree of precision.
• 嵌套和層次結構（Nesting and Hierarchies）：規則可以相互嵌套以創建層次結構，允許創建能夠以高精度精確處理各種情境的複雜決策樹。

This structure ensures that loan policies are applied consistently and fairly, with the flexibility to accommodate exceptions and special cases. It allows for granular control over the lending process, ensuring that resources are allocated efficiently and in accordance with the library's policies.

這種結構確保借貸政策能夠一致且公平地應用，同時具有足夠的靈活性以適應例外情況和特殊案例。它允許對借貸過程進行細粒度的控制，確保資源按照圖書館的政策高效分配。