[SERIES]-[FREQUENCY][SUFFIX]
   |         |         |
   |         |         +-- Temperature grade + packaging (e.g., MAAJ-T)
   |         +-- Frequency value (e.g., 12.000M = 12 MHz)
   +-- 2-character series code (7M, 8Y, 9C, 7V, 7X, AX)

7M-12.000MAAJ-T
|    |    || |
|    |    || +-- T = Tape and Reel packaging
|    |    |+-- J = Package variant
|    |    +-- A = Commercial temperature (-20 to +70C)
|    +-- 12.000M = 12 MHz frequency
+-- 7M = Standard crystal series

8Y-16.000MAAE-T
|    |    ||
|    |    |+-- E = Extended temperature (-40 to +85C)
|    |    +-- A = Tolerance code
|    +-- 16.000M = 16 MHz
+-- 8Y = SMD crystal series

9C-25.000MBD-T
|    |    |
|    |    +-- BD = Clock oscillator suffix
|    +-- 25.000M = 25 MHz
+-- 9C = Clock oscillator series

Commercial (A) can be upgraded to Extended (E)
Extended (E) CANNOT be downgraded to Commercial (A)

// Series is first 2 characters
String extractSeriesCode(String mpn) {
    if (mpn == null || mpn.length() < 2) return "";
    String prefix = mpn.substring(0, 2).toUpperCase();
    return switch (prefix) {
        case "7M", "8Y", "9C", "7V", "7X", "AX" -> prefix;
        default -> "";
    };
}

// Frequency is after first hyphen, ends with M or K
String extractFrequency(String mpn) {
    int dashIndex = mpn.indexOf('-');
    if (dashIndex < 0) return "";
    String afterDash = mpn.substring(dashIndex + 1);

    // Find end of frequency (M for MHz, K for kHz)
    for (int i = 0; i < afterDash.length(); i++) {
        char c = afterDash.charAt(i);
        if (c == 'M' || c == 'K') {
            return afterDash.substring(0, i + 1);
        }
    }
    return "";
}

// Look for E (Extended) or A (Commercial) in options suffix
String extractTemperatureGrade(String mpn) {
    // Remove trailing -T if present
    String workMpn = mpn.endsWith("-T") ? mpn.substring(0, mpn.length() - 2) : mpn;

    // Find options suffix after frequency
    // E anywhere = Extended, A anywhere = Commercial
    String optionsSuffix = /* extract suffix after frequency */;
    if (optionsSuffix.contains("E")) return "Extended";
    if (optionsSuffix.contains("A")) return "Commercial";
    return "";
}