Web pages provide valuable knowledge for human comprehension in text, tables, and mathematical notations. However, the extraction and maintenance of structured rules from the Web pages are not easy tasks. To tackle these problems, we adopt the eXtensible Rule Markup Language framework. The RIML (Rule Identification Markup Language) and RSML (Rule Structure Markup Language) are two compliant representations in XRML for this purpose. RIML identifies the implicit rules in the Web pages possibly using multiple pages to make a rule or rule group. RSML specifies the complete rule structure to be processed by software agents or expert systems. In this study, we cover the natural text, tables, and implicit numeric functions in the texts. In order to fulfill the research goal, we define the necessary tags for the rule extraction and maintenance in XRML. Typical ones include tags for rule grouping, tabular rules, numeric operators, and functions. The rule acquisition process consists of rule base design, rule identification with RIML, and rule structuring with RSML. The maintenance process for the revisions that may occur either in Web pages and structured rules is also described. The approach is demonstrated with the shipping cost comparison on the electronic book stores.